Add m-esr52 at 52.6.0

1 files changed, 9783 insertions, 0 deletions

diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
new file mode 100644
index 0000000000..29d28f8cea
--- /dev/null
+++ b/dom/base/nsContentUtils.cpp
@@ -0,0 +1,9783 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* A namespace class for static layout utilities. */
+
+#include "nsContentUtils.h"
+
+#include <algorithm>
+#include <math.h>
+
+#include "DecoderTraits.h"
+#include "harfbuzz/hb.h"
+#include "imgICache.h"
+#include "imgIContainer.h"
+#include "imgINotificationObserver.h"
+#include "imgLoader.h"
+#include "imgRequestProxy.h"
+#include "jsapi.h"
+#include "jsfriendapi.h"
+#include "js/Value.h"
+#include "Layers.h"
+#include "MediaDecoder.h"
+// nsNPAPIPluginInstance must be included before nsIDocument.h, which is included in mozAutoDocUpdate.h.
+#include "nsNPAPIPluginInstance.h"
+#include "gfxDrawable.h"
+#include "gfxPrefs.h"
+#include "ImageOps.h"
+#include "mozAutoDocUpdate.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/AutoRestore.h"
+#include "mozilla/AutoTimelineMarker.h"
+#include "mozilla/Base64.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/LoadInfo.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/CustomElementRegistry.h"
+#include "mozilla/dom/DocumentFragment.h"
+#include "mozilla/dom/DOMTypes.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/FileSystemSecurity.h"
+#include "mozilla/dom/HTMLMediaElement.h"
+#include "mozilla/dom/HTMLTemplateElement.h"
+#include "mozilla/dom/HTMLContentElement.h"
+#include "mozilla/dom/HTMLShadowElement.h"
+#include "mozilla/dom/ipc/BlobChild.h"
+#include "mozilla/dom/ipc/BlobParent.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/dom/TabParent.h"
+#include "mozilla/dom/TextDecoder.h"
+#include "mozilla/dom/TouchEvent.h"
+#include "mozilla/dom/ShadowRoot.h"
+#include "mozilla/dom/WorkerPrivate.h"
+#include "mozilla/dom/workers/ServiceWorkerManager.h"
+#include "mozilla/EventDispatcher.h"
+#include "mozilla/EventListenerManager.h"
+#include "mozilla/EventStateManager.h"
+#include "mozilla/gfx/DataSurfaceHelpers.h"
+#include "mozilla/IMEStateManager.h"
+#include "mozilla/InternalMutationEvent.h"
+#include "mozilla/Likely.h"
+#include "mozilla/MouseEvents.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/dom/Selection.h"
+#include "mozilla/TextEvents.h"
+#include "nsArrayUtils.h"
+#include "nsAString.h"
+#include "nsAttrName.h"
+#include "nsAttrValue.h"
+#include "nsAttrValueInlines.h"
+#include "nsBindingManager.h"
+#include "nsCaret.h"
+#include "nsCCUncollectableMarker.h"
+#include "nsCharSeparatedTokenizer.h"
+#include "nsCOMPtr.h"
+#include "nsContentCreatorFunctions.h"
+#include "nsContentDLF.h"
+#include "nsContentList.h"
+#include "nsContentPolicyUtils.h"
+#include "nsContentSecurityManager.h"
+#include "nsCPrefetchService.h"
+#include "nsCRT.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsCycleCollector.h"
+#include "nsDataHashtable.h"
+#include "nsDocShellCID.h"
+#include "nsDocument.h"
+#include "nsDOMCID.h"
+#include "mozilla/dom/DataTransfer.h"
+#include "nsDOMJSUtils.h"
+#include "nsDOMMutationObserver.h"
+#include "nsError.h"
+#include "nsFocusManager.h"
+#include "nsGenericHTMLElement.h"
+#include "nsGenericHTMLFrameElement.h"
+#include "nsGkAtoms.h"
+#include "nsHostObjectProtocolHandler.h"
+#include "nsHtml5Module.h"
+#include "nsHtml5StringParser.h"
+#include "nsIAddonPolicyService.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsICategoryManager.h"
+#include "nsIChannelEventSink.h"
+#include "nsICharsetDetectionObserver.h"
+#include "nsIChromeRegistry.h"
+#include "nsIConsoleService.h"
+#include "nsIContent.h"
+#include "nsIContentInlines.h"
+#include "nsIContentSecurityPolicy.h"
+#include "nsIContentSink.h"
+#include "nsIContentViewer.h"
+#include "nsIDocShell.h"
+#include "nsIDocShellTreeOwner.h"
+#include "nsIDocument.h"
+#include "nsIDocumentEncoder.h"
+#include "nsIDOMChromeWindow.h"
+#include "nsIDOMDocument.h"
+#include "nsIDOMDocumentType.h"
+#include "nsIDOMEvent.h"
+#include "nsIDOMElement.h"
+#include "nsIDOMHTMLElement.h"
+#include "nsIDOMHTMLFormElement.h"
+#include "nsIDOMHTMLInputElement.h"
+#include "nsIDOMNode.h"
+#include "nsIDOMNodeList.h"
+#include "nsIDOMWindowUtils.h"
+#include "nsIDOMXULCommandEvent.h"
+#include "nsIDragService.h"
+#include "nsIEditor.h"
+#include "nsIFormControl.h"
+#include "nsIForm.h"
+#include "nsIFragmentContentSink.h"
+#include "nsContainerFrame.h"
+#include "nsIHTMLDocument.h"
+#include "nsIIdleService.h"
+#include "nsIImageLoadingContent.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIIOService.h"
+#include "nsILineBreaker.h"
+#include "nsILoadContext.h"
+#include "nsILoadGroup.h"
+#include "nsIMemoryReporter.h"
+#include "nsIMIMEHeaderParam.h"
+#include "nsIMIMEService.h"
+#include "nsINode.h"
+#include "mozilla/dom/NodeInfo.h"
+#include "nsIObjectLoadingContent.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "nsIOfflineCacheUpdate.h"
+#include "nsIParser.h"
+#include "nsIParserService.h"
+#include "nsIPermissionManager.h"
+#include "nsIPluginHost.h"
+#include "nsIRequest.h"
+#include "nsIRunnable.h"
+#include "nsIScriptContext.h"
+#include "nsIScriptError.h"
+#include "nsIScriptGlobalObject.h"
+#include "nsIScriptObjectPrincipal.h"
+#include "nsIScriptSecurityManager.h"
+#include "nsIScrollable.h"
+#include "nsIStreamConverterService.h"
+#include "nsIStringBundle.h"
+#include "nsIURI.h"
+#include "nsIURIWithPrincipal.h"
+#include "nsIURL.h"
+#include "nsIWebNavigation.h"
+#include "nsIWindowMediator.h"
+#include "nsIWordBreaker.h"
+#include "nsIXPConnect.h"
+#include "nsJSUtils.h"
+#include "nsLWBrkCIID.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsNodeInfoManager.h"
+#include "nsNullPrincipal.h"
+#include "nsParserCIID.h"
+#include "nsParserConstants.h"
+#include "nsPIDOMWindow.h"
+#include "nsPresContext.h"
+#include "nsPrintfCString.h"
+#include "nsReferencedElement.h"
+#include "nsSandboxFlags.h"
+#include "nsScriptSecurityManager.h"
+#include "nsStreamUtils.h"
+#include "nsTextEditorState.h"
+#include "nsTextFragment.h"
+#include "nsTextNode.h"
+#include "nsThreadUtils.h"
+#include "nsUnicharUtilCIID.h"
+#include "nsUnicodeProperties.h"
+#include "nsViewManager.h"
+#include "nsViewportInfo.h"
+#include "nsWidgetsCID.h"
+#include "nsIWindowProvider.h"
+#include "nsWrapperCacheInlines.h"
+#include "nsXULPopupManager.h"
+#include "xpcprivate.h" // nsXPConnect
+#include "HTMLSplitOnSpacesTokenizer.h"
+#include "nsContentTypeParser.h"
+#include "nsICookiePermission.h"
+#include "mozIThirdPartyUtil.h"
+#include "nsICookieService.h"
+#include "mozilla/EnumSet.h"
+#include "mozilla/BloomFilter.h"
+#include "TabChild.h"
+#include "mozilla/dom/DocGroup.h"
+#include "mozilla/dom/TabGroup.h"
+
+#include "nsIBidiKeyboard.h"
+
+#if defined(XP_WIN)
+// Undefine LoadImage to prevent naming conflict with Windows.
+#undef LoadImage
+#endif
+
+extern "C" int MOZ_XMLTranslateEntity(const char* ptr, const char* end,
+                                      const char** next, char16_t* result);
+extern "C" int MOZ_XMLCheckQName(const char* ptr, const char* end,
+                                 int ns_aware, const char** colon);
+
+class imgLoader;
+
+using namespace mozilla::dom;
+using namespace mozilla::ipc;
+using namespace mozilla::gfx;
+using namespace mozilla::layers;
+using namespace mozilla::widget;
+using namespace mozilla;
+
+const char kLoadAsData[] = "loadAsData";
+
+nsIXPConnect *nsContentUtils::sXPConnect;
+nsIScriptSecurityManager *nsContentUtils::sSecurityManager;
+nsIPrincipal *nsContentUtils::sSystemPrincipal;
+nsIPrincipal *nsContentUtils::sNullSubjectPrincipal;
+nsIParserService *nsContentUtils::sParserService = nullptr;
+nsNameSpaceManager *nsContentUtils::sNameSpaceManager;
+nsIIOService *nsContentUtils::sIOService;
+nsIUUIDGenerator *nsContentUtils::sUUIDGenerator;
+nsIConsoleService *nsContentUtils::sConsoleService;
+nsDataHashtable<nsISupportsHashKey, EventNameMapping>* nsContentUtils::sAtomEventTable = nullptr;
+nsDataHashtable<nsStringHashKey, EventNameMapping>* nsContentUtils::sStringEventTable = nullptr;
+nsCOMArray<nsIAtom>* nsContentUtils::sUserDefinedEvents = nullptr;
+nsIStringBundleService *nsContentUtils::sStringBundleService;
+nsIStringBundle *nsContentUtils::sStringBundles[PropertiesFile_COUNT];
+nsIContentPolicy *nsContentUtils::sContentPolicyService;
+bool nsContentUtils::sTriedToGetContentPolicy = false;
+nsILineBreaker *nsContentUtils::sLineBreaker;
+nsIWordBreaker *nsContentUtils::sWordBreaker;
+nsIBidiKeyboard *nsContentUtils::sBidiKeyboard = nullptr;
+uint32_t nsContentUtils::sScriptBlockerCount = 0;
+uint32_t nsContentUtils::sDOMNodeRemovedSuppressCount = 0;
+uint32_t nsContentUtils::sMicroTaskLevel = 0;
+AutoTArray<nsCOMPtr<nsIRunnable>, 8>* nsContentUtils::sBlockedScriptRunners = nullptr;
+uint32_t nsContentUtils::sRunnersCountAtFirstBlocker = 0;
+nsIInterfaceRequestor* nsContentUtils::sSameOriginChecker = nullptr;
+
+bool nsContentUtils::sIsHandlingKeyBoardEvent = false;
+bool nsContentUtils::sAllowXULXBL_for_file = false;
+
+nsString* nsContentUtils::sShiftText = nullptr;
+nsString* nsContentUtils::sControlText = nullptr;
+nsString* nsContentUtils::sMetaText = nullptr;
+nsString* nsContentUtils::sOSText = nullptr;
+nsString* nsContentUtils::sAltText = nullptr;
+nsString* nsContentUtils::sModifierSeparator = nullptr;
+
+bool nsContentUtils::sInitialized = false;
+bool nsContentUtils::sIsFullScreenApiEnabled = false;
+bool nsContentUtils::sIsUnprefixedFullscreenApiEnabled = false;
+bool nsContentUtils::sTrustedFullScreenOnly = true;
+bool nsContentUtils::sIsCutCopyAllowed = true;
+bool nsContentUtils::sIsFrameTimingPrefEnabled = false;
+bool nsContentUtils::sIsPerformanceTimingEnabled = false;
+bool nsContentUtils::sIsResourceTimingEnabled = false;
+bool nsContentUtils::sIsUserTimingLoggingEnabled = false;
+bool nsContentUtils::sIsExperimentalAutocompleteEnabled = false;
+bool nsContentUtils::sEncodeDecodeURLHash = false;
+bool nsContentUtils::sGettersDecodeURLHash = false;
+bool nsContentUtils::sPrivacyResistFingerprinting = false;
+bool nsContentUtils::sSendPerformanceTimingNotifications = false;
+bool nsContentUtils::sUseActivityCursor = false;
+
+uint32_t nsContentUtils::sHandlingInputTimeout = 1000;
+
+uint32_t nsContentUtils::sCookiesLifetimePolicy = nsICookieService::ACCEPT_NORMALLY;
+uint32_t nsContentUtils::sCookiesBehavior = nsICookieService::BEHAVIOR_ACCEPT;
+
+nsHtml5StringParser* nsContentUtils::sHTMLFragmentParser = nullptr;
+nsIParser* nsContentUtils::sXMLFragmentParser = nullptr;
+nsIFragmentContentSink* nsContentUtils::sXMLFragmentSink = nullptr;
+bool nsContentUtils::sFragmentParsingActive = false;
+
+#if !(defined(DEBUG) || defined(MOZ_ENABLE_JS_DUMP))
+bool nsContentUtils::sDOMWindowDumpEnabled;
+#endif
+
+bool nsContentUtils::sDoNotTrackEnabled = false;
+
+mozilla::LazyLogModule nsContentUtils::sDOMDumpLog("Dump");
+
+// Subset of http://www.whatwg.org/specs/web-apps/current-work/#autofill-field-name
+enum AutocompleteFieldName : uint8_t
+{
+  #define AUTOCOMPLETE_FIELD_NAME(name_, value_) \
+    eAutocompleteFieldName_##name_,
+  #define AUTOCOMPLETE_CONTACT_FIELD_NAME(name_, value_) \
+    AUTOCOMPLETE_FIELD_NAME(name_, value_)
+  #include "AutocompleteFieldList.h"
+  #undef AUTOCOMPLETE_FIELD_NAME
+  #undef AUTOCOMPLETE_CONTACT_FIELD_NAME
+};
+
+enum AutocompleteFieldHint : uint8_t
+{
+  #define AUTOCOMPLETE_FIELD_HINT(name_, value_) \
+    eAutocompleteFieldHint_##name_,
+  #include "AutocompleteFieldList.h"
+  #undef AUTOCOMPLETE_FIELD_HINT
+};
+
+enum AutocompleteFieldContactHint : uint8_t
+{
+  #define AUTOCOMPLETE_FIELD_CONTACT_HINT(name_, value_) \
+    eAutocompleteFieldContactHint_##name_,
+  #include "AutocompleteFieldList.h"
+  #undef AUTOCOMPLETE_FIELD_CONTACT_HINT
+};
+
+enum AutocompleteCategory
+{
+  #define AUTOCOMPLETE_CATEGORY(name_, value_) eAutocompleteCategory_##name_,
+  #include "AutocompleteFieldList.h"
+  #undef AUTOCOMPLETE_CATEGORY
+};
+
+static const nsAttrValue::EnumTable kAutocompleteFieldNameTable[] = {
+  #define AUTOCOMPLETE_FIELD_NAME(name_, value_) \
+    { value_, eAutocompleteFieldName_##name_ },
+  #include "AutocompleteFieldList.h"
+  #undef AUTOCOMPLETE_FIELD_NAME
+  { nullptr, 0 }
+};
+
+static const nsAttrValue::EnumTable kAutocompleteContactFieldNameTable[] = {
+  #define AUTOCOMPLETE_CONTACT_FIELD_NAME(name_, value_) \
+    { value_, eAutocompleteFieldName_##name_ },
+  #include "AutocompleteFieldList.h"
+  #undef AUTOCOMPLETE_CONTACT_FIELD_NAME
+  { nullptr, 0 }
+};
+
+static const nsAttrValue::EnumTable kAutocompleteFieldHintTable[] = {
+  #define AUTOCOMPLETE_FIELD_HINT(name_, value_) \
+    { value_, eAutocompleteFieldHint_##name_ },
+  #include "AutocompleteFieldList.h"
+  #undef AUTOCOMPLETE_FIELD_HINT
+  { nullptr, 0 }
+};
+
+static const nsAttrValue::EnumTable kAutocompleteContactFieldHintTable[] = {
+  #define AUTOCOMPLETE_FIELD_CONTACT_HINT(name_, value_) \
+    { value_, eAutocompleteFieldContactHint_##name_ },
+  #include "AutocompleteFieldList.h"
+  #undef AUTOCOMPLETE_FIELD_CONTACT_HINT
+  { nullptr, 0 }
+};
+
+namespace {
+
+static NS_DEFINE_CID(kParserServiceCID, NS_PARSERSERVICE_CID);
+static NS_DEFINE_CID(kCParserCID, NS_PARSER_CID);
+
+static PLDHashTable* sEventListenerManagersHash;
+
+class DOMEventListenerManagersHashReporter final : public nsIMemoryReporter
+{
+  MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)
+
+  ~DOMEventListenerManagersHashReporter() {}
+
+public:
+  NS_DECL_ISUPPORTS
+
+  NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
+                            nsISupports* aData, bool aAnonymize) override
+  {
+    // We don't measure the |EventListenerManager| objects pointed to by the
+    // entries because those references are non-owning.
+    int64_t amount = sEventListenerManagersHash
+                   ? sEventListenerManagersHash->ShallowSizeOfIncludingThis(
+                       MallocSizeOf)
+                   : 0;
+
+    MOZ_COLLECT_REPORT(
+      "explicit/dom/event-listener-managers-hash", KIND_HEAP, UNITS_BYTES,
+      amount,
+      "Memory used by the event listener manager's hash table.");
+
+    return NS_OK;
+  }
+};
+
+NS_IMPL_ISUPPORTS(DOMEventListenerManagersHashReporter, nsIMemoryReporter)
+
+class EventListenerManagerMapEntry : public PLDHashEntryHdr
+{
+public:
+  explicit EventListenerManagerMapEntry(const void* aKey)
+    : mKey(aKey)
+  {
+  }
+
+  ~EventListenerManagerMapEntry()
+  {
+    NS_ASSERTION(!mListenerManager, "caller must release and disconnect ELM");
+  }
+
+protected:          // declared protected to silence clang warnings
+  const void *mKey; // must be first, to look like PLDHashEntryStub
+
+public:
+  RefPtr<EventListenerManager> mListenerManager;
+};
+
+static void
+EventListenerManagerHashInitEntry(PLDHashEntryHdr *entry, const void *key)
+{
+  // Initialize the entry with placement new
+  new (entry) EventListenerManagerMapEntry(key);
+}
+
+static void
+EventListenerManagerHashClearEntry(PLDHashTable *table, PLDHashEntryHdr *entry)
+{
+  EventListenerManagerMapEntry *lm =
+    static_cast<EventListenerManagerMapEntry *>(entry);
+
+  // Let the EventListenerManagerMapEntry clean itself up...
+  lm->~EventListenerManagerMapEntry();
+}
+
+class SameOriginCheckerImpl final : public nsIChannelEventSink,
+                                    public nsIInterfaceRequestor
+{
+  ~SameOriginCheckerImpl() {}
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSICHANNELEVENTSINK
+  NS_DECL_NSIINTERFACEREQUESTOR
+};
+
+class CharsetDetectionObserver final : public nsICharsetDetectionObserver
+{
+public:
+  NS_DECL_ISUPPORTS
+
+  NS_IMETHOD Notify(const char *aCharset, nsDetectionConfident aConf) override
+  {
+    mCharset = aCharset;
+    return NS_OK;
+  }
+
+  const nsACString& GetResult() const
+  {
+    return mCharset;
+  }
+
+private:
+  nsCString mCharset;
+};
+
+} // namespace
+
+/* static */
+TimeDuration
+nsContentUtils::HandlingUserInputTimeout()
+{
+  return TimeDuration::FromMilliseconds(sHandlingInputTimeout);
+}
+
+// static
+nsresult
+nsContentUtils::Init()
+{
+  if (sInitialized) {
+    NS_WARNING("Init() called twice");
+
+    return NS_OK;
+  }
+
+  sNameSpaceManager = nsNameSpaceManager::GetInstance();
+  NS_ENSURE_TRUE(sNameSpaceManager, NS_ERROR_OUT_OF_MEMORY);
+
+  sXPConnect = nsXPConnect::XPConnect();
+
+  sSecurityManager = nsScriptSecurityManager::GetScriptSecurityManager();
+  if(!sSecurityManager)
+    return NS_ERROR_FAILURE;
+  NS_ADDREF(sSecurityManager);
+
+  sSecurityManager->GetSystemPrincipal(&sSystemPrincipal);
+  MOZ_ASSERT(sSystemPrincipal);
+
+  // We use the constructor here because we want infallible initialization; we
+  // apparently don't care whether sNullSubjectPrincipal has a sane URI or not.
+  RefPtr<nsNullPrincipal> nullPrincipal = new nsNullPrincipal();
+  nullPrincipal->Init();
+  nullPrincipal.forget(&sNullSubjectPrincipal);
+
+  nsresult rv = CallGetService(NS_IOSERVICE_CONTRACTID, &sIOService);
+  if (NS_FAILED(rv)) {
+    // This makes life easier, but we can live without it.
+
+    sIOService = nullptr;
+  }
+
+  rv = CallGetService(NS_LBRK_CONTRACTID, &sLineBreaker);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = CallGetService(NS_WBRK_CONTRACTID, &sWordBreaker);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!InitializeEventTable())
+    return NS_ERROR_FAILURE;
+
+  if (!sEventListenerManagersHash) {
+    static const PLDHashTableOps hash_table_ops =
+    {
+      PLDHashTable::HashVoidPtrKeyStub,
+      PLDHashTable::MatchEntryStub,
+      PLDHashTable::MoveEntryStub,
+      EventListenerManagerHashClearEntry,
+      EventListenerManagerHashInitEntry
+    };
+
+    sEventListenerManagersHash =
+      new PLDHashTable(&hash_table_ops, sizeof(EventListenerManagerMapEntry));
+
+    RegisterStrongMemoryReporter(new DOMEventListenerManagersHashReporter());
+  }
+
+  sBlockedScriptRunners = new AutoTArray<nsCOMPtr<nsIRunnable>, 8>;
+
+  Preferences::AddBoolVarCache(&sAllowXULXBL_for_file,
+                               "dom.allow_XUL_XBL_for_file");
+
+  Preferences::AddBoolVarCache(&sIsFullScreenApiEnabled,
+                               "full-screen-api.enabled");
+
+  Preferences::AddBoolVarCache(&sIsUnprefixedFullscreenApiEnabled,
+                               "full-screen-api.unprefix.enabled");
+
+  Preferences::AddBoolVarCache(&sTrustedFullScreenOnly,
+                               "full-screen-api.allow-trusted-requests-only");
+
+  Preferences::AddBoolVarCache(&sIsCutCopyAllowed,
+                               "dom.allow_cut_copy", true);
+
+  Preferences::AddBoolVarCache(&sIsPerformanceTimingEnabled,
+                               "dom.enable_performance", true);
+
+  Preferences::AddBoolVarCache(&sIsResourceTimingEnabled,
+                               "dom.enable_resource_timing", true);
+
+  Preferences::AddBoolVarCache(&sIsUserTimingLoggingEnabled,
+                               "dom.performance.enable_user_timing_logging", false);
+
+  Preferences::AddBoolVarCache(&sIsFrameTimingPrefEnabled,
+                               "dom.enable_frame_timing", false);
+
+  Preferences::AddBoolVarCache(&sIsExperimentalAutocompleteEnabled,
+                               "dom.forms.autocomplete.experimental", false);
+
+  Preferences::AddBoolVarCache(&sEncodeDecodeURLHash,
+                               "dom.url.encode_decode_hash", false);
+
+  Preferences::AddBoolVarCache(&sGettersDecodeURLHash,
+                               "dom.url.getters_decode_hash", false);
+
+  Preferences::AddBoolVarCache(&sPrivacyResistFingerprinting,
+                               "privacy.resistFingerprinting", false);
+
+  Preferences::AddUintVarCache(&sHandlingInputTimeout,
+                               "dom.event.handling-user-input-time-limit",
+                               1000);
+
+  Preferences::AddBoolVarCache(&sSendPerformanceTimingNotifications,
+                               "dom.performance.enable_notify_performance_timing", false);
+
+  Preferences::AddUintVarCache(&sCookiesLifetimePolicy,
+                               "network.cookie.lifetimePolicy",
+                               nsICookieService::ACCEPT_NORMALLY);
+
+  Preferences::AddUintVarCache(&sCookiesBehavior,
+                               "network.cookie.cookieBehavior",
+                               nsICookieService::BEHAVIOR_ACCEPT);
+
+#if !(defined(DEBUG) || defined(MOZ_ENABLE_JS_DUMP))
+  Preferences::AddBoolVarCache(&sDOMWindowDumpEnabled,
+                               "browser.dom.window.dump.enabled");
+#endif
+
+  Preferences::AddBoolVarCache(&sDoNotTrackEnabled,
+                               "privacy.donottrackheader.enabled", false);
+
+  Preferences::AddBoolVarCache(&sUseActivityCursor,
+                               "ui.use_activity_cursor", false);
+
+  Element::InitCCCallbacks();
+
+  nsCOMPtr<nsIUUIDGenerator> uuidGenerator =
+    do_GetService("@mozilla.org/uuid-generator;1", &rv);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  uuidGenerator.forget(&sUUIDGenerator);
+
+  sInitialized = true;
+
+  return NS_OK;
+}
+
+void
+nsContentUtils::GetShiftText(nsAString& text)
+{
+  if (!sShiftText)
+    InitializeModifierStrings();
+  text.Assign(*sShiftText);
+}
+
+void
+nsContentUtils::GetControlText(nsAString& text)
+{
+  if (!sControlText)
+    InitializeModifierStrings();
+  text.Assign(*sControlText);
+}
+
+void
+nsContentUtils::GetMetaText(nsAString& text)
+{
+  if (!sMetaText)
+    InitializeModifierStrings();
+  text.Assign(*sMetaText);
+}
+
+void
+nsContentUtils::GetOSText(nsAString& text)
+{
+  if (!sOSText) {
+    InitializeModifierStrings();
+  }
+  text.Assign(*sOSText);
+}
+
+void
+nsContentUtils::GetAltText(nsAString& text)
+{
+  if (!sAltText)
+    InitializeModifierStrings();
+  text.Assign(*sAltText);
+}
+
+void
+nsContentUtils::GetModifierSeparatorText(nsAString& text)
+{
+  if (!sModifierSeparator)
+    InitializeModifierStrings();
+  text.Assign(*sModifierSeparator);
+}
+
+void
+nsContentUtils::InitializeModifierStrings()
+{
+  //load the display strings for the keyboard accelerators
+  nsCOMPtr<nsIStringBundleService> bundleService =
+    mozilla::services::GetStringBundleService();
+  nsCOMPtr<nsIStringBundle> bundle;
+  DebugOnly<nsresult> rv = NS_OK;
+  if (bundleService) {
+    rv = bundleService->CreateBundle( "chrome://global-platform/locale/platformKeys.properties",
+                                      getter_AddRefs(bundle));
+  }
+
+  NS_ASSERTION(NS_SUCCEEDED(rv) && bundle, "chrome://global/locale/platformKeys.properties could not be loaded");
+  nsXPIDLString shiftModifier;
+  nsXPIDLString metaModifier;
+  nsXPIDLString osModifier;
+  nsXPIDLString altModifier;
+  nsXPIDLString controlModifier;
+  nsXPIDLString modifierSeparator;
+  if (bundle) {
+    //macs use symbols for each modifier key, so fetch each from the bundle, which also covers i18n
+    bundle->GetStringFromName(u"VK_SHIFT", getter_Copies(shiftModifier));
+    bundle->GetStringFromName(u"VK_META", getter_Copies(metaModifier));
+    bundle->GetStringFromName(u"VK_WIN", getter_Copies(osModifier));
+    bundle->GetStringFromName(u"VK_ALT", getter_Copies(altModifier));
+    bundle->GetStringFromName(u"VK_CONTROL", getter_Copies(controlModifier));
+    bundle->GetStringFromName(u"MODIFIER_SEPARATOR", getter_Copies(modifierSeparator));
+  }
+  //if any of these don't exist, we get  an empty string
+  sShiftText = new nsString(shiftModifier);
+  sMetaText = new nsString(metaModifier);
+  sOSText = new nsString(osModifier);
+  sAltText = new nsString(altModifier);
+  sControlText = new nsString(controlModifier);
+  sModifierSeparator = new nsString(modifierSeparator);
+}
+
+// Because of SVG/SMIL we have several atoms mapped to the same
+// id, but we can rely on MESSAGE_TO_EVENT to map id to only one atom.
+static bool
+ShouldAddEventToStringEventTable(const EventNameMapping& aMapping)
+{
+  switch(aMapping.mMessage) {
+#define MESSAGE_TO_EVENT(name_, message_, type_, struct_) \
+  case message_: return nsGkAtoms::on##name_ == aMapping.mAtom;
+#include "mozilla/EventNameList.h"
+#undef MESSAGE_TO_EVENT
+  default:
+    break;
+  }
+  return false;
+}
+
+bool
+nsContentUtils::InitializeEventTable() {
+  NS_ASSERTION(!sAtomEventTable, "EventTable already initialized!");
+  NS_ASSERTION(!sStringEventTable, "EventTable already initialized!");
+
+  static const EventNameMapping eventArray[] = {
+#define EVENT(name_,  _message, _type, _class)          \
+    { nsGkAtoms::on##name_, _type, _message, _class, false },
+#define WINDOW_ONLY_EVENT EVENT
+#define NON_IDL_EVENT EVENT
+#include "mozilla/EventNameList.h"
+#undef WINDOW_ONLY_EVENT
+#undef NON_IDL_EVENT
+#undef EVENT
+    { nullptr }
+  };
+
+  sAtomEventTable = new nsDataHashtable<nsISupportsHashKey, EventNameMapping>(
+      ArrayLength(eventArray));
+  sStringEventTable = new nsDataHashtable<nsStringHashKey, EventNameMapping>(
+      ArrayLength(eventArray));
+  sUserDefinedEvents = new nsCOMArray<nsIAtom>(64);
+
+  // Subtract one from the length because of the trailing null
+  for (uint32_t i = 0; i < ArrayLength(eventArray) - 1; ++i) {
+    sAtomEventTable->Put(eventArray[i].mAtom, eventArray[i]);
+    if (ShouldAddEventToStringEventTable(eventArray[i])) {
+      sStringEventTable->Put(
+        Substring(nsDependentAtomString(eventArray[i].mAtom), 2),
+        eventArray[i]);
+    }
+  }
+
+  return true;
+}
+
+void
+nsContentUtils::InitializeTouchEventTable()
+{
+  static bool sEventTableInitialized = false;
+  if (!sEventTableInitialized && sAtomEventTable && sStringEventTable) {
+    sEventTableInitialized = true;
+    static const EventNameMapping touchEventArray[] = {
+#define EVENT(name_,  _message, _type, _class)
+#define TOUCH_EVENT(name_,  _message, _type, _class)      \
+      { nsGkAtoms::on##name_, _type, _message, _class },
+#include "mozilla/EventNameList.h"
+#undef TOUCH_EVENT
+#undef EVENT
+      { nullptr }
+    };
+    // Subtract one from the length because of the trailing null
+    for (uint32_t i = 0; i < ArrayLength(touchEventArray) - 1; ++i) {
+      sAtomEventTable->Put(touchEventArray[i].mAtom, touchEventArray[i]);
+      sStringEventTable->Put(Substring(nsDependentAtomString(touchEventArray[i].mAtom), 2),
+                             touchEventArray[i]);
+    }
+  }
+}
+
+static bool
+Is8bit(const nsAString& aString)
+{
+  static const char16_t EIGHT_BIT = char16_t(~0x00FF);
+
+  for (nsAString::const_char_iterator start = aString.BeginReading(),
+         end = aString.EndReading();
+       start != end;
+       ++start) {
+    if (*start & EIGHT_BIT) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+nsresult
+nsContentUtils::Btoa(const nsAString& aBinaryData,
+                     nsAString& aAsciiBase64String)
+{
+  if (!Is8bit(aBinaryData)) {
+    aAsciiBase64String.Truncate();
+    return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
+  }
+
+  return Base64Encode(aBinaryData, aAsciiBase64String);
+}
+
+nsresult
+nsContentUtils::Atob(const nsAString& aAsciiBase64String,
+                     nsAString& aBinaryData)
+{
+  if (!Is8bit(aAsciiBase64String)) {
+    aBinaryData.Truncate();
+    return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
+  }
+
+  const char16_t* start = aAsciiBase64String.BeginReading();
+  const char16_t* end = aAsciiBase64String.EndReading();
+  nsString trimmedString;
+  if (!trimmedString.SetCapacity(aAsciiBase64String.Length(), fallible)) {
+    return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
+  }
+  while (start < end) {
+    if (!nsContentUtils::IsHTMLWhitespace(*start)) {
+      trimmedString.Append(*start);
+    }
+    start++;
+  }
+  nsresult rv = Base64Decode(trimmedString, aBinaryData);
+  if (NS_FAILED(rv) && rv == NS_ERROR_INVALID_ARG) {
+    return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
+  }
+  return rv;
+}
+
+bool
+nsContentUtils::IsAutocompleteEnabled(nsIDOMHTMLInputElement* aInput)
+{
+  NS_PRECONDITION(aInput, "aInput should not be null!");
+
+  nsAutoString autocomplete;
+  aInput->GetAutocomplete(autocomplete);
+
+  if (autocomplete.IsEmpty()) {
+    nsCOMPtr<nsIDOMHTMLFormElement> form;
+    aInput->GetForm(getter_AddRefs(form));
+    if (!form) {
+      return true;
+    }
+
+    form->GetAutocomplete(autocomplete);
+  }
+
+  return !autocomplete.EqualsLiteral("off");
+}
+
+nsContentUtils::AutocompleteAttrState
+nsContentUtils::SerializeAutocompleteAttribute(const nsAttrValue* aAttr,
+                                               nsAString& aResult,
+                                               AutocompleteAttrState aCachedState)
+{
+  if (!aAttr ||
+      aCachedState == nsContentUtils::eAutocompleteAttrState_Invalid) {
+    return aCachedState;
+  }
+
+  if (aCachedState == nsContentUtils::eAutocompleteAttrState_Valid) {
+    uint32_t atomCount = aAttr->GetAtomCount();
+    for (uint32_t i = 0; i < atomCount; i++) {
+      if (i != 0) {
+        aResult.Append(' ');
+      }
+      aResult.Append(nsDependentAtomString(aAttr->AtomAt(i)));
+    }
+    nsContentUtils::ASCIIToLower(aResult);
+    return aCachedState;
+  }
+
+  aResult.Truncate();
+
+  mozilla::dom::AutocompleteInfo info;
+  AutocompleteAttrState state =
+    InternalSerializeAutocompleteAttribute(aAttr, info);
+  if (state == eAutocompleteAttrState_Valid) {
+    // Concatenate the info fields.
+    aResult = info.mSection;
+
+    if (!info.mAddressType.IsEmpty()) {
+      if (!aResult.IsEmpty()) {
+        aResult += ' ';
+      }
+      aResult += info.mAddressType;
+    }
+
+    if (!info.mContactType.IsEmpty()) {
+      if (!aResult.IsEmpty()) {
+        aResult += ' ';
+      }
+      aResult += info.mContactType;
+    }
+
+    if (!info.mFieldName.IsEmpty()) {
+      if (!aResult.IsEmpty()) {
+        aResult += ' ';
+      }
+      aResult += info.mFieldName;
+    }
+  }
+
+  return state;
+}
+
+nsContentUtils::AutocompleteAttrState
+nsContentUtils::SerializeAutocompleteAttribute(const nsAttrValue* aAttr,
+                                               mozilla::dom::AutocompleteInfo& aInfo,
+                                               AutocompleteAttrState aCachedState)
+{
+  if (!aAttr ||
+      aCachedState == nsContentUtils::eAutocompleteAttrState_Invalid) {
+    return aCachedState;
+  }
+
+  return InternalSerializeAutocompleteAttribute(aAttr, aInfo);
+}
+
+/**
+ * Helper to validate the @autocomplete tokens.
+ *
+ * @return {AutocompleteAttrState} The state of the attribute (invalid/valid).
+ */
+nsContentUtils::AutocompleteAttrState
+nsContentUtils::InternalSerializeAutocompleteAttribute(const nsAttrValue* aAttrVal,
+                                                       mozilla::dom::AutocompleteInfo& aInfo)
+{
+  // No sandbox attribute so we are done
+  if (!aAttrVal) {
+    return eAutocompleteAttrState_Invalid;
+  }
+
+  uint32_t numTokens = aAttrVal->GetAtomCount();
+  if (!numTokens) {
+    return eAutocompleteAttrState_Invalid;
+  }
+
+  uint32_t index = numTokens - 1;
+  nsString tokenString = nsDependentAtomString(aAttrVal->AtomAt(index));
+  AutocompleteCategory category;
+  nsAttrValue enumValue;
+
+  nsAutoString str;
+  bool result = enumValue.ParseEnumValue(tokenString, kAutocompleteFieldNameTable, false);
+  if (result) {
+    // Off/Automatic/Normal categories.
+    if (enumValue.Equals(NS_LITERAL_STRING("off"), eIgnoreCase) ||
+        enumValue.Equals(NS_LITERAL_STRING("on"), eIgnoreCase)) {
+      if (numTokens > 1) {
+        return eAutocompleteAttrState_Invalid;
+      }
+      enumValue.ToString(str);
+      ASCIIToLower(str);
+      aInfo.mFieldName.Assign(str);
+      return eAutocompleteAttrState_Valid;
+    }
+
+    // Only allow on/off if experimental @autocomplete values aren't enabled.
+    if (!sIsExperimentalAutocompleteEnabled) {
+      return eAutocompleteAttrState_Invalid;
+    }
+
+    // Normal category
+    if (numTokens > 2) {
+      return eAutocompleteAttrState_Invalid;
+    }
+    category = eAutocompleteCategory_NORMAL;
+  } else { // Check if the last token is of the contact category instead.
+    // Only allow on/off if experimental @autocomplete values aren't enabled.
+    if (!sIsExperimentalAutocompleteEnabled) {
+      return eAutocompleteAttrState_Invalid;
+    }
+
+    result = enumValue.ParseEnumValue(tokenString, kAutocompleteContactFieldNameTable, false);
+    if (!result || numTokens > 3) {
+      return eAutocompleteAttrState_Invalid;
+    }
+
+    category = eAutocompleteCategory_CONTACT;
+  }
+
+  enumValue.ToString(str);
+  ASCIIToLower(str);
+  aInfo.mFieldName.Assign(str);
+
+  // We are done if this was the only token.
+  if (numTokens == 1) {
+    return eAutocompleteAttrState_Valid;
+  }
+
+  --index;
+  tokenString = nsDependentAtomString(aAttrVal->AtomAt(index));
+
+  if (category == eAutocompleteCategory_CONTACT) {
+    nsAttrValue contactFieldHint;
+    result = contactFieldHint.ParseEnumValue(tokenString, kAutocompleteContactFieldHintTable, false);
+    if (result) {
+      nsAutoString contactFieldHintString;
+      contactFieldHint.ToString(contactFieldHintString);
+      ASCIIToLower(contactFieldHintString);
+      aInfo.mContactType.Assign(contactFieldHintString);
+      if (index == 0) {
+        return eAutocompleteAttrState_Valid;
+      }
+      --index;
+      tokenString = nsDependentAtomString(aAttrVal->AtomAt(index));
+    }
+  }
+
+  // Check for billing/shipping tokens
+  nsAttrValue fieldHint;
+  if (fieldHint.ParseEnumValue(tokenString, kAutocompleteFieldHintTable, false)) {
+    nsString fieldHintString;
+    fieldHint.ToString(fieldHintString);
+    ASCIIToLower(fieldHintString);
+    aInfo.mAddressType.Assign(fieldHintString);
+    if (index == 0) {
+      return eAutocompleteAttrState_Valid;
+    }
+    --index;
+  }
+
+  // Clear the fields as the autocomplete attribute is invalid.
+  aInfo.mAddressType.Truncate();
+  aInfo.mContactType.Truncate();
+  aInfo.mFieldName.Truncate();
+
+  return eAutocompleteAttrState_Invalid;
+}
+
+// Parse an integer according to HTML spec
+int32_t
+nsContentUtils::ParseHTMLInteger(const nsAString& aValue,
+                                 ParseHTMLIntegerResultFlags *aResult)
+{
+  int result = eParseHTMLInteger_NoFlags;
+
+  nsAString::const_iterator iter, end;
+  aValue.BeginReading(iter);
+  aValue.EndReading(end);
+
+  while (iter != end && nsContentUtils::IsHTMLWhitespace(*iter)) {
+    result |= eParseHTMLInteger_NonStandard;
+    ++iter;
+  }
+
+  if (iter == end) {
+    result |= eParseHTMLInteger_Error | eParseHTMLInteger_ErrorNoValue;
+    *aResult = (ParseHTMLIntegerResultFlags)result;
+    return 0;
+  }
+
+  int sign = 1;
+  if (*iter == char16_t('-')) {
+    sign = -1;
+    ++iter;
+  } else if (*iter == char16_t('+')) {
+    result |= eParseHTMLInteger_NonStandard;
+    ++iter;
+  }
+
+  bool foundValue = false;
+  CheckedInt32 value = 0;
+
+  // Check for leading zeros first.
+  uint64_t leadingZeros = 0;
+  while (iter != end) {
+    if (*iter != char16_t('0')) {
+      break;
+    }
+
+    ++leadingZeros;
+    foundValue = true;
+    ++iter;
+  }
+
+  while (iter != end) {
+    if (*iter >= char16_t('0') && *iter <= char16_t('9')) {
+      value = (value * 10) + (*iter - char16_t('0')) * sign;
+      ++iter;
+      if (!value.isValid()) {
+        result |= eParseHTMLInteger_Error | eParseHTMLInteger_ErrorOverflow;
+        break;
+      } else {
+        foundValue = true;
+      }
+    } else if (*iter == char16_t('%')) {
+      ++iter;
+      result |= eParseHTMLInteger_IsPercent;
+      break;
+    } else {
+      break;
+    }
+  }
+
+  if (!foundValue) {
+    result |= eParseHTMLInteger_Error | eParseHTMLInteger_ErrorNoValue;
+  }
+
+  if (value.isValid() &&
+       ((leadingZeros > 1 || (leadingZeros == 1 && !(value == 0))) ||
+       (sign == -1 && value == 0))) {
+    result |= eParseHTMLInteger_NonStandard;
+  }
+
+  if (iter != end) {
+    result |= eParseHTMLInteger_DidNotConsumeAllInput;
+  }
+
+  *aResult = (ParseHTMLIntegerResultFlags)result;
+  return value.isValid() ? value.value() : 0;
+}
+
+#define SKIP_WHITESPACE(iter, end_iter, end_res)                 \
+  while ((iter) != (end_iter) && nsCRT::IsAsciiSpace(*(iter))) { \
+    ++(iter);                                                    \
+  }                                                              \
+  if ((iter) == (end_iter)) {                                    \
+    return (end_res);                                            \
+  }
+
+#define SKIP_ATTR_NAME(iter, end_iter)                            \
+  while ((iter) != (end_iter) && !nsCRT::IsAsciiSpace(*(iter)) && \
+         *(iter) != '=') {                                        \
+    ++(iter);                                                     \
+  }
+
+bool
+nsContentUtils::GetPseudoAttributeValue(const nsString& aSource, nsIAtom *aName,
+                                        nsAString& aValue)
+{
+  aValue.Truncate();
+
+  const char16_t *start = aSource.get();
+  const char16_t *end = start + aSource.Length();
+  const char16_t *iter;
+
+  while (start != end) {
+    SKIP_WHITESPACE(start, end, false)
+    iter = start;
+    SKIP_ATTR_NAME(iter, end)
+
+    if (start == iter) {
+      return false;
+    }
+
+    // Remember the attr name.
+    const nsDependentSubstring & attrName = Substring(start, iter);
+
+    // Now check whether this is a valid name="value" pair.
+    start = iter;
+    SKIP_WHITESPACE(start, end, false)
+    if (*start != '=') {
+      // No '=', so this is not a name="value" pair.  We don't know
+      // what it is, and we have no way to handle it.
+      return false;
+    }
+
+    // Have to skip the value.
+    ++start;
+    SKIP_WHITESPACE(start, end, false)
+    char16_t q = *start;
+    if (q != kQuote && q != kApostrophe) {
+      // Not a valid quoted value, so bail.
+      return false;
+    }
+
+    ++start;  // Point to the first char of the value.
+    iter = start;
+
+    while (iter != end && *iter != q) {
+      ++iter;
+    }
+
+    if (iter == end) {
+      // Oops, unterminated quoted string.
+      return false;
+    }
+
+    // At this point attrName holds the name of the "attribute" and
+    // the value is between start and iter.
+
+    if (aName->Equals(attrName)) {
+      // We'll accumulate as many characters as possible (until we hit either
+      // the end of the string or the beginning of an entity). Chunks will be
+      // delimited by start and chunkEnd.
+      const char16_t *chunkEnd = start;
+      while (chunkEnd != iter) {
+        if (*chunkEnd == kLessThan) {
+          aValue.Truncate();
+
+          return false;
+        }
+
+        if (*chunkEnd == kAmpersand) {
+          aValue.Append(start, chunkEnd - start);
+
+          const char16_t *afterEntity = nullptr;
+          char16_t result[2];
+          uint32_t count =
+            MOZ_XMLTranslateEntity(reinterpret_cast<const char*>(chunkEnd),
+                                   reinterpret_cast<const char*>(iter),
+                                   reinterpret_cast<const char**>(&afterEntity),
+                                   result);
+          if (count == 0) {
+            aValue.Truncate();
+
+            return false;
+          }
+
+          aValue.Append(result, count);
+
+          // Advance to after the entity and begin a new chunk.
+          start = chunkEnd = afterEntity;
+        }
+        else {
+          ++chunkEnd;
+        }
+      }
+
+      // Append remainder.
+      aValue.Append(start, iter - start);
+
+      return true;
+    }
+
+    // Resume scanning after the end of the attribute value (past the quote
+    // char).
+    start = iter + 1;
+  }
+
+  return false;
+}
+
+bool
+nsContentUtils::IsJavaScriptLanguage(const nsString& aName)
+{
+  return aName.LowerCaseEqualsLiteral("javascript") ||
+         aName.LowerCaseEqualsLiteral("livescript") ||
+         aName.LowerCaseEqualsLiteral("mocha") ||
+         aName.LowerCaseEqualsLiteral("javascript1.0") ||
+         aName.LowerCaseEqualsLiteral("javascript1.1") ||
+         aName.LowerCaseEqualsLiteral("javascript1.2") ||
+         aName.LowerCaseEqualsLiteral("javascript1.3") ||
+         aName.LowerCaseEqualsLiteral("javascript1.4") ||
+         aName.LowerCaseEqualsLiteral("javascript1.5");
+}
+
+JSVersion
+nsContentUtils::ParseJavascriptVersion(const nsAString& aVersionStr)
+{
+  if (aVersionStr.Length() != 3 || aVersionStr[0] != '1' ||
+      aVersionStr[1] != '.') {
+    return JSVERSION_UNKNOWN;
+  }
+
+  switch (aVersionStr[2]) {
+  case '0': /* fall through */
+  case '1': /* fall through */
+  case '2': /* fall through */
+  case '3': /* fall through */
+  case '4': /* fall through */
+  case '5': return JSVERSION_DEFAULT;
+  case '6': return JSVERSION_1_6;
+  case '7': return JSVERSION_1_7;
+  case '8': return JSVERSION_1_8;
+  default:  return JSVERSION_UNKNOWN;
+  }
+}
+
+void
+nsContentUtils::SplitMimeType(const nsAString& aValue, nsString& aType,
+                              nsString& aParams)
+{
+  aType.Truncate();
+  aParams.Truncate();
+  int32_t semiIndex = aValue.FindChar(char16_t(';'));
+  if (-1 != semiIndex) {
+    aType = Substring(aValue, 0, semiIndex);
+    aParams = Substring(aValue, semiIndex + 1,
+                       aValue.Length() - (semiIndex + 1));
+    aParams.StripWhitespace();
+  }
+  else {
+    aType = aValue;
+  }
+  aType.StripWhitespace();
+}
+
+nsresult
+nsContentUtils::IsUserIdle(uint32_t aRequestedIdleTimeInMS, bool* aUserIsIdle)
+{
+  nsresult rv;
+  nsCOMPtr<nsIIdleService> idleService =
+    do_GetService("@mozilla.org/widget/idleservice;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint32_t idleTimeInMS;
+  rv = idleService->GetIdleTime(&idleTimeInMS);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *aUserIsIdle = idleTimeInMS >= aRequestedIdleTimeInMS;
+  return NS_OK;
+}
+
+/**
+ * Access a cached parser service. Don't addref. We need only one
+ * reference to it and this class has that one.
+ */
+/* static */
+nsIParserService*
+nsContentUtils::GetParserService()
+{
+  // XXX: This isn't accessed from several threads, is it?
+  if (!sParserService) {
+    // Lock, recheck sCachedParserService and aquire if this should be
+    // safe for multiple threads.
+    nsresult rv = CallGetService(kParserServiceCID, &sParserService);
+    if (NS_FAILED(rv)) {
+      sParserService = nullptr;
+    }
+  }
+
+  return sParserService;
+}
+
+/**
+* A helper function that parses a sandbox attribute (of an <iframe> or a CSP
+* directive) and converts it to the set of flags used internally.
+*
+* @param aSandboxAttr  the sandbox attribute
+* @return              the set of flags (SANDBOXED_NONE if aSandboxAttr is
+*                      null)
+*/
+uint32_t
+nsContentUtils::ParseSandboxAttributeToFlags(const nsAttrValue* aSandboxAttr)
+{
+  if (!aSandboxAttr) {
+    return SANDBOXED_NONE;
+  }
+
+  uint32_t out = SANDBOX_ALL_FLAGS;
+
+#define SANDBOX_KEYWORD(string, atom, flags)                  \
+  if (aSandboxAttr->Contains(nsGkAtoms::atom, eIgnoreCase)) { \
+    out &= ~(flags);                                          \
+  }
+#include "IframeSandboxKeywordList.h"
+#undef SANDBOX_KEYWORD
+
+  return out;
+}
+
+/**
+* A helper function that checks if a string matches a valid sandbox flag.
+*
+* @param aFlag   the potential sandbox flag.
+* @return        true if the flag is a sandbox flag.
+*/
+bool
+nsContentUtils::IsValidSandboxFlag(const nsAString& aFlag)
+{
+#define SANDBOX_KEYWORD(string, atom, flags)                                  \
+  if (EqualsIgnoreASCIICase(nsDependentAtomString(nsGkAtoms::atom), aFlag)) { \
+    return true;                                                              \
+  }
+#include "IframeSandboxKeywordList.h"
+#undef SANDBOX_KEYWORD
+  return false;
+}
+
+/**
+ * A helper function that returns a string attribute corresponding to the
+ * sandbox flags.
+ *
+ * @param aFlags    the sandbox flags
+ * @param aString   the attribute corresponding to the flags (null if aFlags
+ *                  is zero)
+ */
+void
+nsContentUtils::SandboxFlagsToString(uint32_t aFlags, nsAString& aString)
+{
+  if (!aFlags) {
+    SetDOMStringToNull(aString);
+    return;
+  }
+
+  aString.Truncate();
+
+#define SANDBOX_KEYWORD(string, atom, flags)                \
+  if (!(aFlags & (flags))) {                                \
+    if (!aString.IsEmpty()) {                               \
+      aString.Append(NS_LITERAL_STRING(" "));               \
+    }                                                       \
+    aString.Append(nsDependentAtomString(nsGkAtoms::atom)); \
+  }
+#include "IframeSandboxKeywordList.h"
+#undef SANDBOX_KEYWORD
+}
+
+nsIBidiKeyboard*
+nsContentUtils::GetBidiKeyboard()
+{
+  if (!sBidiKeyboard) {
+    nsresult rv = CallGetService("@mozilla.org/widget/bidikeyboard;1", &sBidiKeyboard);
+    if (NS_FAILED(rv)) {
+      sBidiKeyboard = nullptr;
+    }
+  }
+  return sBidiKeyboard;
+}
+
+template <class OutputIterator>
+struct NormalizeNewlinesCharTraits {
+  public:
+    typedef typename OutputIterator::value_type value_type;
+
+  public:
+    explicit NormalizeNewlinesCharTraits(OutputIterator& aIterator) : mIterator(aIterator) { }
+    void writechar(typename OutputIterator::value_type aChar) {
+      *mIterator++ = aChar;
+    }
+
+  private:
+    OutputIterator mIterator;
+};
+
+template <class CharT>
+struct NormalizeNewlinesCharTraits<CharT*> {
+  public:
+    typedef CharT value_type;
+
+  public:
+    explicit NormalizeNewlinesCharTraits(CharT* aCharPtr) : mCharPtr(aCharPtr) { }
+    void writechar(CharT aChar) {
+      *mCharPtr++ = aChar;
+    }
+
+  private:
+    CharT* mCharPtr;
+};
+
+template <class OutputIterator>
+class CopyNormalizeNewlines
+{
+  public:
+    typedef typename OutputIterator::value_type value_type;
+
+  public:
+    explicit CopyNormalizeNewlines(OutputIterator* aDestination,
+                                   bool aLastCharCR = false) :
+      mLastCharCR(aLastCharCR),
+      mDestination(aDestination),
+      mWritten(0)
+    { }
+
+    uint32_t GetCharsWritten() {
+      return mWritten;
+    }
+
+    bool IsLastCharCR() {
+      return mLastCharCR;
+    }
+
+    void write(const typename OutputIterator::value_type* aSource, uint32_t aSourceLength) {
+
+      const typename OutputIterator::value_type* done_writing = aSource + aSourceLength;
+
+      // If the last source buffer ended with a CR...
+      if (mLastCharCR) {
+        // ..and if the next one is a LF, then skip it since
+        // we've already written out a newline
+        if (aSourceLength && (*aSource == value_type('\n'))) {
+          ++aSource;
+        }
+        mLastCharCR = false;
+      }
+
+      uint32_t num_written = 0;
+      while ( aSource < done_writing ) {
+        if (*aSource == value_type('\r')) {
+          mDestination->writechar('\n');
+          ++aSource;
+          // If we've reached the end of the buffer, record
+          // that we wrote out a CR
+          if (aSource == done_writing) {
+            mLastCharCR = true;
+          }
+          // If the next character is a LF, skip it
+          else if (*aSource == value_type('\n')) {
+            ++aSource;
+          }
+        }
+        else {
+          mDestination->writechar(*aSource++);
+        }
+        ++num_written;
+      }
+
+      mWritten += num_written;
+    }
+
+  private:
+    bool mLastCharCR;
+    OutputIterator* mDestination;
+    uint32_t mWritten;
+};
+
+// static
+uint32_t
+nsContentUtils::CopyNewlineNormalizedUnicodeTo(const nsAString& aSource,
+                                               uint32_t aSrcOffset,
+                                               char16_t* aDest,
+                                               uint32_t aLength,
+                                               bool& aLastCharCR)
+{
+  typedef NormalizeNewlinesCharTraits<char16_t*> sink_traits;
+
+  sink_traits dest_traits(aDest);
+  CopyNormalizeNewlines<sink_traits> normalizer(&dest_traits,aLastCharCR);
+  nsReadingIterator<char16_t> fromBegin, fromEnd;
+  copy_string(aSource.BeginReading(fromBegin).advance( int32_t(aSrcOffset) ),
+              aSource.BeginReading(fromEnd).advance( int32_t(aSrcOffset+aLength) ),
+              normalizer);
+  aLastCharCR = normalizer.IsLastCharCR();
+  return normalizer.GetCharsWritten();
+}
+
+// static
+uint32_t
+nsContentUtils::CopyNewlineNormalizedUnicodeTo(nsReadingIterator<char16_t>& aSrcStart, const nsReadingIterator<char16_t>& aSrcEnd, nsAString& aDest)
+{
+  typedef nsWritingIterator<char16_t> WritingIterator;
+  typedef NormalizeNewlinesCharTraits<WritingIterator> sink_traits;
+
+  WritingIterator iter;
+  aDest.BeginWriting(iter);
+  sink_traits dest_traits(iter);
+  CopyNormalizeNewlines<sink_traits> normalizer(&dest_traits);
+  copy_string(aSrcStart, aSrcEnd, normalizer);
+  return normalizer.GetCharsWritten();
+}
+
+/**
+ * This is used to determine whether a character is in one of the classes
+ * which CSS says should be part of the first-letter.  Currently, that is
+ * all punctuation classes (P*).  Note that this is a change from CSS2
+ * which excluded Pc and Pd.
+ *
+ * https://www.w3.org/TR/css-pseudo-4/#first-letter-pseudo
+ * "Punctuation (i.e, characters that belong to the Punctuation (P*) Unicode
+ *  general category [UAX44]) [...]"
+ */
+
+// static
+bool
+nsContentUtils::IsFirstLetterPunctuation(uint32_t aChar)
+{
+  switch (mozilla::unicode::GetGeneralCategory(aChar)) {
+    case HB_UNICODE_GENERAL_CATEGORY_CONNECT_PUNCTUATION: /* Pc */
+    case HB_UNICODE_GENERAL_CATEGORY_DASH_PUNCTUATION:    /* Pd */
+    case HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION:   /* Pe */
+    case HB_UNICODE_GENERAL_CATEGORY_FINAL_PUNCTUATION:   /* Pf */
+    case HB_UNICODE_GENERAL_CATEGORY_INITIAL_PUNCTUATION: /* Pi */
+    case HB_UNICODE_GENERAL_CATEGORY_OTHER_PUNCTUATION:   /* Po */
+    case HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION:    /* Ps */
+      return true;
+    default:
+      return false;
+  }
+}
+
+// static
+bool
+nsContentUtils::IsFirstLetterPunctuationAt(const nsTextFragment* aFrag, uint32_t aOffset)
+{
+  char16_t h = aFrag->CharAt(aOffset);
+  if (!IS_SURROGATE(h)) {
+    return IsFirstLetterPunctuation(h);
+  }
+  if (NS_IS_HIGH_SURROGATE(h) && aOffset + 1 < aFrag->GetLength()) {
+    char16_t l = aFrag->CharAt(aOffset + 1);
+    if (NS_IS_LOW_SURROGATE(l)) {
+      return IsFirstLetterPunctuation(SURROGATE_TO_UCS4(h, l));
+    }
+  }
+  return false;
+}
+
+// static
+bool nsContentUtils::IsAlphanumeric(uint32_t aChar)
+{
+  nsIUGenCategory::nsUGenCategory cat = mozilla::unicode::GetGenCategory(aChar);
+
+  return (cat == nsIUGenCategory::kLetter || cat == nsIUGenCategory::kNumber);
+}
+
+// static
+bool nsContentUtils::IsAlphanumericAt(const nsTextFragment* aFrag, uint32_t aOffset)
+{
+  char16_t h = aFrag->CharAt(aOffset);
+  if (!IS_SURROGATE(h)) {
+    return IsAlphanumeric(h);
+  }
+  if (NS_IS_HIGH_SURROGATE(h) && aOffset + 1 < aFrag->GetLength()) {
+    char16_t l = aFrag->CharAt(aOffset + 1);
+    if (NS_IS_LOW_SURROGATE(l)) {
+      return IsAlphanumeric(SURROGATE_TO_UCS4(h, l));
+    }
+  }
+  return false;
+}
+
+/* static */
+bool
+nsContentUtils::IsHTMLWhitespace(char16_t aChar)
+{
+  return aChar == char16_t(0x0009) ||
+         aChar == char16_t(0x000A) ||
+         aChar == char16_t(0x000C) ||
+         aChar == char16_t(0x000D) ||
+         aChar == char16_t(0x0020);
+}
+
+/* static */
+bool
+nsContentUtils::IsHTMLWhitespaceOrNBSP(char16_t aChar)
+{
+  return IsHTMLWhitespace(aChar) || aChar == char16_t(0xA0);
+}
+
+/* static */
+bool
+nsContentUtils::IsHTMLBlock(nsIContent* aContent)
+{
+  return aContent->IsAnyOfHTMLElements(nsGkAtoms::address,
+                                       nsGkAtoms::article,
+                                       nsGkAtoms::aside,
+                                       nsGkAtoms::blockquote,
+                                       nsGkAtoms::center,
+                                       nsGkAtoms::dir,
+                                       nsGkAtoms::div,
+                                       nsGkAtoms::dl, // XXX why not dt and dd?
+                                       nsGkAtoms::fieldset,
+                                       nsGkAtoms::figure, // XXX shouldn't figcaption be on this list
+                                       nsGkAtoms::footer,
+                                       nsGkAtoms::form,
+                                       nsGkAtoms::h1,
+                                       nsGkAtoms::h2,
+                                       nsGkAtoms::h3,
+                                       nsGkAtoms::h4,
+                                       nsGkAtoms::h5,
+                                       nsGkAtoms::h6,
+                                       nsGkAtoms::header,
+                                       nsGkAtoms::hgroup,
+                                       nsGkAtoms::hr,
+                                       nsGkAtoms::li,
+                                       nsGkAtoms::listing,
+                                       nsGkAtoms::menu,
+                                       nsGkAtoms::multicol, // XXX get rid of this one?
+                                       nsGkAtoms::nav,
+                                       nsGkAtoms::ol,
+                                       nsGkAtoms::p,
+                                       nsGkAtoms::pre,
+                                       nsGkAtoms::section,
+                                       nsGkAtoms::table,
+                                       nsGkAtoms::ul,
+                                       nsGkAtoms::xmp);
+}
+
+/* static */
+bool
+nsContentUtils::ParseIntMarginValue(const nsAString& aString, nsIntMargin& result)
+{
+  nsAutoString marginStr(aString);
+  marginStr.CompressWhitespace(true, true);
+  if (marginStr.IsEmpty()) {
+    return false;
+  }
+
+  int32_t start = 0, end = 0;
+  for (int count = 0; count < 4; count++) {
+    if ((uint32_t)end >= marginStr.Length())
+      return false;
+
+    // top, right, bottom, left
+    if (count < 3)
+      end = Substring(marginStr, start).FindChar(',');
+    else
+      end = Substring(marginStr, start).Length();
+
+    if (end <= 0)
+      return false;
+
+    nsresult ec;
+    int32_t val = nsString(Substring(marginStr, start, end)).ToInteger(&ec);
+    if (NS_FAILED(ec))
+      return false;
+
+    switch(count) {
+      case 0:
+        result.top = val;
+      break;
+      case 1:
+        result.right = val;
+      break;
+      case 2:
+        result.bottom = val;
+      break;
+      case 3:
+        result.left = val;
+      break;
+    }
+    start += end + 1;
+  }
+  return true;
+}
+
+// static
+int32_t
+nsContentUtils::ParseLegacyFontSize(const nsAString& aValue)
+{
+  nsAString::const_iterator iter, end;
+  aValue.BeginReading(iter);
+  aValue.EndReading(end);
+
+  while (iter != end && nsContentUtils::IsHTMLWhitespace(*iter)) {
+    ++iter;
+  }
+
+  if (iter == end) {
+    return 0;
+  }
+
+  bool relative = false;
+  bool negate = false;
+  if (*iter == char16_t('-')) {
+    relative = true;
+    negate = true;
+    ++iter;
+  } else if (*iter == char16_t('+')) {
+    relative = true;
+    ++iter;
+  }
+
+  if (iter == end || *iter < char16_t('0') || *iter > char16_t('9')) {
+    return 0;
+  }
+
+  // We don't have to worry about overflow, since we can bail out as soon as
+  // we're bigger than 7.
+  int32_t value = 0;
+  while (iter != end && *iter >= char16_t('0') && *iter <= char16_t('9')) {
+    value = 10*value + (*iter - char16_t('0'));
+    if (value >= 7) {
+      break;
+    }
+    ++iter;
+  }
+
+  if (relative) {
+    if (negate) {
+      value = 3 - value;
+    } else {
+      value = 3 + value;
+    }
+  }
+
+  return clamped(value, 1, 7);
+}
+
+/* static */
+bool
+nsContentUtils::IsControlledByServiceWorker(nsIDocument* aDocument)
+{
+  if (nsContentUtils::IsInPrivateBrowsing(aDocument)) {
+    return false;
+  }
+
+  RefPtr<workers::ServiceWorkerManager> swm =
+    workers::ServiceWorkerManager::GetInstance();
+  MOZ_ASSERT(swm);
+
+  ErrorResult rv;
+  bool controlled = swm->IsControlled(aDocument, rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+    return false;
+  }
+
+  return controlled;
+}
+
+/* static */
+void
+nsContentUtils::GetOfflineAppManifest(nsIDocument *aDocument, nsIURI **aURI)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aDocument);
+  *aURI = nullptr;
+
+  if (IsControlledByServiceWorker(aDocument)) {
+    return;
+  }
+
+  Element* docElement = aDocument->GetRootElement();
+  if (!docElement) {
+    return;
+  }
+
+  nsAutoString manifestSpec;
+  docElement->GetAttr(kNameSpaceID_None, nsGkAtoms::manifest, manifestSpec);
+
+  // Manifest URIs can't have fragment identifiers.
+  if (manifestSpec.IsEmpty() ||
+      manifestSpec.Contains('#')) {
+    return;
+  }
+
+  nsContentUtils::NewURIWithDocumentCharset(aURI, manifestSpec,
+                                            aDocument,
+                                            aDocument->GetDocBaseURI());
+}
+
+/* static */
+bool
+nsContentUtils::OfflineAppAllowed(nsIURI *aURI)
+{
+  nsCOMPtr<nsIOfflineCacheUpdateService> updateService =
+    do_GetService(NS_OFFLINECACHEUPDATESERVICE_CONTRACTID);
+  if (!updateService) {
+    return false;
+  }
+
+  bool allowed;
+  nsresult rv =
+    updateService->OfflineAppAllowedForURI(aURI,
+                                           Preferences::GetRootBranch(),
+                                           &allowed);
+  return NS_SUCCEEDED(rv) && allowed;
+}
+
+/* static */
+bool
+nsContentUtils::OfflineAppAllowed(nsIPrincipal *aPrincipal)
+{
+  nsCOMPtr<nsIOfflineCacheUpdateService> updateService =
+    do_GetService(NS_OFFLINECACHEUPDATESERVICE_CONTRACTID);
+  if (!updateService) {
+    return false;
+  }
+
+  bool allowed;
+  nsresult rv = updateService->OfflineAppAllowed(aPrincipal,
+                                                 Preferences::GetRootBranch(),
+                                                 &allowed);
+  return NS_SUCCEEDED(rv) && allowed;
+}
+
+bool
+nsContentUtils::MaybeAllowOfflineAppByDefault(nsIPrincipal *aPrincipal)
+{
+  if (!Preferences::GetRootBranch())
+    return false;
+
+  nsresult rv;
+
+  bool allowedByDefault;
+  rv = Preferences::GetRootBranch()->GetBoolPref(
+    "offline-apps.allow_by_default", &allowedByDefault);
+  if (NS_FAILED(rv))
+    return false;
+
+  if (!allowedByDefault)
+    return false;
+
+  nsCOMPtr<nsIOfflineCacheUpdateService> updateService =
+    do_GetService(NS_OFFLINECACHEUPDATESERVICE_CONTRACTID);
+  if (!updateService) {
+    return false;
+  }
+
+  rv = updateService->AllowOfflineApp(aPrincipal);
+  return NS_SUCCEEDED(rv);
+}
+
+// static
+void
+nsContentUtils::Shutdown()
+{
+  sInitialized = false;
+
+  NS_IF_RELEASE(sContentPolicyService);
+  sTriedToGetContentPolicy = false;
+  uint32_t i;
+  for (i = 0; i < PropertiesFile_COUNT; ++i)
+    NS_IF_RELEASE(sStringBundles[i]);
+
+  NS_IF_RELEASE(sStringBundleService);
+  NS_IF_RELEASE(sConsoleService);
+  sXPConnect = nullptr;
+  NS_IF_RELEASE(sSecurityManager);
+  NS_IF_RELEASE(sSystemPrincipal);
+  NS_IF_RELEASE(sNullSubjectPrincipal);
+  NS_IF_RELEASE(sParserService);
+  NS_IF_RELEASE(sIOService);
+  NS_IF_RELEASE(sUUIDGenerator);
+  NS_IF_RELEASE(sLineBreaker);
+  NS_IF_RELEASE(sWordBreaker);
+  NS_IF_RELEASE(sBidiKeyboard);
+
+  delete sAtomEventTable;
+  sAtomEventTable = nullptr;
+  delete sStringEventTable;
+  sStringEventTable = nullptr;
+  delete sUserDefinedEvents;
+  sUserDefinedEvents = nullptr;
+
+  if (sEventListenerManagersHash) {
+    NS_ASSERTION(sEventListenerManagersHash->EntryCount() == 0,
+                 "Event listener manager hash not empty at shutdown!");
+
+    // See comment above.
+
+    // However, we have to handle this table differently.  If it still
+    // has entries, we want to leak it too, so that we can keep it alive
+    // in case any elements are destroyed.  Because if they are, we need
+    // their event listener managers to be destroyed too, or otherwise
+    // it could leave dangling references in DOMClassInfo's preserved
+    // wrapper table.
+
+    if (sEventListenerManagersHash->EntryCount() == 0) {
+      delete sEventListenerManagersHash;
+      sEventListenerManagersHash = nullptr;
+    }
+  }
+
+  NS_ASSERTION(!sBlockedScriptRunners ||
+               sBlockedScriptRunners->Length() == 0,
+               "How'd this happen?");
+  delete sBlockedScriptRunners;
+  sBlockedScriptRunners = nullptr;
+
+  delete sShiftText;
+  sShiftText = nullptr;
+  delete sControlText;
+  sControlText = nullptr;
+  delete sMetaText;
+  sMetaText = nullptr;
+  delete sOSText;
+  sOSText = nullptr;
+  delete sAltText;
+  sAltText = nullptr;
+  delete sModifierSeparator;
+  sModifierSeparator = nullptr;
+
+  NS_IF_RELEASE(sSameOriginChecker);
+}
+
+/**
+ * Checks whether two nodes come from the same origin. aTrustedNode is
+ * considered 'safe' in that a user can operate on it and that it isn't
+ * a js-object that implements nsIDOMNode.
+ * Never call this function with the first node provided by script, it
+ * must always be known to be a 'real' node!
+ */
+// static
+nsresult
+nsContentUtils::CheckSameOrigin(const nsINode *aTrustedNode,
+                                nsIDOMNode *aUnTrustedNode)
+{
+  MOZ_ASSERT(aTrustedNode);
+
+  // Make sure it's a real node.
+  nsCOMPtr<nsINode> unTrustedNode = do_QueryInterface(aUnTrustedNode);
+  NS_ENSURE_TRUE(unTrustedNode, NS_ERROR_UNEXPECTED);
+  return CheckSameOrigin(aTrustedNode, unTrustedNode);
+}
+
+nsresult
+nsContentUtils::CheckSameOrigin(const nsINode* aTrustedNode,
+                                const nsINode* unTrustedNode)
+{
+  MOZ_ASSERT(aTrustedNode);
+  MOZ_ASSERT(unTrustedNode);
+
+  /*
+   * Get hold of each node's principal
+   */
+
+  nsIPrincipal* trustedPrincipal = aTrustedNode->NodePrincipal();
+  nsIPrincipal* unTrustedPrincipal = unTrustedNode->NodePrincipal();
+
+  if (trustedPrincipal == unTrustedPrincipal) {
+    return NS_OK;
+  }
+
+  bool equal;
+  // XXXbz should we actually have a Subsumes() check here instead?  Or perhaps
+  // a separate method for that, with callers using one or the other?
+  if (NS_FAILED(trustedPrincipal->Equals(unTrustedPrincipal, &equal)) ||
+      !equal) {
+    return NS_ERROR_DOM_PROP_ACCESS_DENIED;
+  }
+
+  return NS_OK;
+}
+
+// static
+bool
+nsContentUtils::CanCallerAccess(nsIPrincipal* aSubjectPrincipal,
+                                nsIPrincipal* aPrincipal)
+{
+  bool subsumes;
+  nsresult rv = aSubjectPrincipal->Subsumes(aPrincipal, &subsumes);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  if (subsumes) {
+    return true;
+  }
+
+  // The subject doesn't subsume aPrincipal. Allow access only if the subject
+  // is chrome.
+  return IsCallerChrome();
+}
+
+// static
+bool
+nsContentUtils::CanCallerAccess(nsIDOMNode *aNode)
+{
+  nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
+  NS_ENSURE_TRUE(node, false);
+  return CanCallerAccess(node);
+}
+
+// static
+bool
+nsContentUtils::CanCallerAccess(nsINode* aNode)
+{
+  return CanCallerAccess(SubjectPrincipal(), aNode->NodePrincipal());
+}
+
+// static
+bool
+nsContentUtils::CanCallerAccess(nsPIDOMWindowInner* aWindow)
+{
+  nsCOMPtr<nsIScriptObjectPrincipal> scriptObject = do_QueryInterface(aWindow);
+  NS_ENSURE_TRUE(scriptObject, false);
+
+  return CanCallerAccess(SubjectPrincipal(), scriptObject->GetPrincipal());
+}
+
+//static
+bool
+nsContentUtils::InProlog(nsINode *aNode)
+{
+  NS_PRECONDITION(aNode, "missing node to nsContentUtils::InProlog");
+
+  nsINode* parent = aNode->GetParentNode();
+  if (!parent || !parent->IsNodeOfType(nsINode::eDOCUMENT)) {
+    return false;
+  }
+
+  nsIDocument* doc = static_cast<nsIDocument*>(parent);
+  nsIContent* root = doc->GetRootElement();
+
+  return !root || doc->IndexOf(aNode) < doc->IndexOf(root);
+}
+
+nsIDocument*
+nsContentUtils::GetDocumentFromCaller()
+{
+  AutoJSContext cx;
+
+  nsCOMPtr<nsPIDOMWindowInner> win =
+    do_QueryInterface(nsJSUtils::GetStaticScriptGlobal(JS::CurrentGlobalOrNull(cx)));
+  if (!win) {
+    return nullptr;
+  }
+
+  return win->GetExtantDoc();
+}
+
+bool
+nsContentUtils::IsCallerChrome()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (SubjectPrincipal() == sSystemPrincipal) {
+    return true;
+  }
+
+  // If the check failed, look for UniversalXPConnect on the cx compartment.
+  return xpc::IsUniversalXPConnectEnabled(GetCurrentJSContext());
+}
+
+bool
+nsContentUtils::ShouldResistFingerprinting(nsIDocShell* aDocShell)
+{
+  if (!aDocShell) {
+    return false;
+  }
+  bool isChrome = nsContentUtils::IsChromeDoc(aDocShell->GetDocument());
+  return !isChrome && sPrivacyResistFingerprinting;
+}
+
+namespace mozilla {
+namespace dom {
+namespace workers {
+extern bool IsCurrentThreadRunningChromeWorker();
+extern JSContext* GetCurrentThreadJSContext();
+} // namespace workers
+} // namespace dom
+} // namespace mozilla
+
+bool
+nsContentUtils::ThreadsafeIsCallerChrome()
+{
+  return NS_IsMainThread() ?
+    IsCallerChrome() :
+    mozilla::dom::workers::IsCurrentThreadRunningChromeWorker();
+}
+
+bool
+nsContentUtils::IsCallerContentXBL()
+{
+    JSContext *cx = GetCurrentJSContext();
+    if (!cx)
+        return false;
+
+    JSCompartment *c = js::GetContextCompartment(cx);
+
+    // For remote XUL, we run XBL in the XUL scope. Given that we care about
+    // compat and not security for remote XUL, just always claim to be XBL.
+    if (!xpc::AllowContentXBLScope(c)) {
+      MOZ_ASSERT(nsContentUtils::AllowXULXBLForPrincipal(xpc::GetCompartmentPrincipal(c)));
+      return true;
+    }
+
+    return xpc::IsContentXBLScope(c);
+}
+
+// static
+bool
+nsContentUtils::LookupBindingMember(JSContext* aCx, nsIContent *aContent,
+                                    JS::Handle<jsid> aId,
+                                    JS::MutableHandle<JS::PropertyDescriptor> aDesc)
+{
+  nsXBLBinding* binding = aContent->GetXBLBinding();
+  if (!binding)
+    return true;
+  return binding->LookupMember(aCx, aId, aDesc);
+}
+
+// static
+nsINode*
+nsContentUtils::GetCrossDocParentNode(nsINode* aChild)
+{
+  NS_PRECONDITION(aChild, "The child is null!");
+
+  nsINode* parent = aChild->GetParentNode();
+  if (parent && parent->IsContent() && aChild->IsContent()) {
+    parent = aChild->AsContent()->GetFlattenedTreeParent();
+  }
+
+  if (parent || !aChild->IsNodeOfType(nsINode::eDOCUMENT))
+    return parent;
+
+  nsIDocument* doc = static_cast<nsIDocument*>(aChild);
+  nsIDocument* parentDoc = doc->GetParentDocument();
+  return parentDoc ? parentDoc->FindContentForSubDocument(doc) : nullptr;
+}
+
+// static
+bool
+nsContentUtils::ContentIsDescendantOf(const nsINode* aPossibleDescendant,
+                                      const nsINode* aPossibleAncestor)
+{
+  NS_PRECONDITION(aPossibleDescendant, "The possible descendant is null!");
+  NS_PRECONDITION(aPossibleAncestor, "The possible ancestor is null!");
+
+  do {
+    if (aPossibleDescendant == aPossibleAncestor)
+      return true;
+    aPossibleDescendant = aPossibleDescendant->GetParentNode();
+  } while (aPossibleDescendant);
+
+  return false;
+}
+
+bool
+nsContentUtils::ContentIsHostIncludingDescendantOf(
+  const nsINode* aPossibleDescendant, const nsINode* aPossibleAncestor)
+{
+  NS_PRECONDITION(aPossibleDescendant, "The possible descendant is null!");
+  NS_PRECONDITION(aPossibleAncestor, "The possible ancestor is null!");
+
+  do {
+    if (aPossibleDescendant == aPossibleAncestor)
+      return true;
+    if (aPossibleDescendant->NodeType() == nsIDOMNode::DOCUMENT_FRAGMENT_NODE) {
+      aPossibleDescendant =
+        static_cast<const DocumentFragment*>(aPossibleDescendant)->GetHost();
+    } else {
+      aPossibleDescendant = aPossibleDescendant->GetParentNode();
+    }
+  } while (aPossibleDescendant);
+
+  return false;
+}
+
+// static
+bool
+nsContentUtils::ContentIsCrossDocDescendantOf(nsINode* aPossibleDescendant,
+                                              nsINode* aPossibleAncestor)
+{
+  NS_PRECONDITION(aPossibleDescendant, "The possible descendant is null!");
+  NS_PRECONDITION(aPossibleAncestor, "The possible ancestor is null!");
+
+  do {
+    if (aPossibleDescendant == aPossibleAncestor)
+      return true;
+
+    aPossibleDescendant = GetCrossDocParentNode(aPossibleDescendant);
+  } while (aPossibleDescendant);
+
+  return false;
+}
+
+
+// static
+nsresult
+nsContentUtils::GetAncestors(nsINode* aNode,
+                             nsTArray<nsINode*>& aArray)
+{
+  while (aNode) {
+    aArray.AppendElement(aNode);
+    aNode = aNode->GetParentNode();
+  }
+  return NS_OK;
+}
+
+// static
+nsresult
+nsContentUtils::GetAncestorsAndOffsets(nsIDOMNode* aNode,
+                                       int32_t aOffset,
+                                       nsTArray<nsIContent*>* aAncestorNodes,
+                                       nsTArray<int32_t>* aAncestorOffsets)
+{
+  NS_ENSURE_ARG_POINTER(aNode);
+
+  nsCOMPtr<nsIContent> content(do_QueryInterface(aNode));
+
+  if (!content) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (!aAncestorNodes->IsEmpty()) {
+    NS_WARNING("aAncestorNodes is not empty");
+    aAncestorNodes->Clear();
+  }
+
+  if (!aAncestorOffsets->IsEmpty()) {
+    NS_WARNING("aAncestorOffsets is not empty");
+    aAncestorOffsets->Clear();
+  }
+
+  // insert the node itself
+  aAncestorNodes->AppendElement(content.get());
+  aAncestorOffsets->AppendElement(aOffset);
+
+  // insert all the ancestors
+  nsIContent* child = content;
+  nsIContent* parent = child->GetParent();
+  while (parent) {
+    aAncestorNodes->AppendElement(parent);
+    aAncestorOffsets->AppendElement(parent->IndexOf(child));
+    child = parent;
+    parent = parent->GetParent();
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+nsContentUtils::GetCommonAncestor(nsIDOMNode *aNode,
+                                  nsIDOMNode *aOther,
+                                  nsIDOMNode** aCommonAncestor)
+{
+  *aCommonAncestor = nullptr;
+
+  nsCOMPtr<nsINode> node1 = do_QueryInterface(aNode);
+  nsCOMPtr<nsINode> node2 = do_QueryInterface(aOther);
+
+  NS_ENSURE_TRUE(node1 && node2, NS_ERROR_UNEXPECTED);
+
+  nsINode* common = GetCommonAncestor(node1, node2);
+  NS_ENSURE_TRUE(common, NS_ERROR_NOT_AVAILABLE);
+
+  return CallQueryInterface(common, aCommonAncestor);
+}
+
+// static
+nsINode*
+nsContentUtils::GetCommonAncestor(nsINode* aNode1,
+                                  nsINode* aNode2)
+{
+  if (aNode1 == aNode2) {
+    return aNode1;
+  }
+
+  // Build the chain of parents
+  AutoTArray<nsINode*, 30> parents1, parents2;
+  do {
+    parents1.AppendElement(aNode1);
+    aNode1 = aNode1->GetParentNode();
+  } while (aNode1);
+  do {
+    parents2.AppendElement(aNode2);
+    aNode2 = aNode2->GetParentNode();
+  } while (aNode2);
+
+  // Find where the parent chain differs
+  uint32_t pos1 = parents1.Length();
+  uint32_t pos2 = parents2.Length();
+  nsINode* parent = nullptr;
+  uint32_t len;
+  for (len = std::min(pos1, pos2); len > 0; --len) {
+    nsINode* child1 = parents1.ElementAt(--pos1);
+    nsINode* child2 = parents2.ElementAt(--pos2);
+    if (child1 != child2) {
+      break;
+    }
+    parent = child1;
+  }
+
+  return parent;
+}
+
+/* static */
+bool
+nsContentUtils::PositionIsBefore(nsINode* aNode1, nsINode* aNode2)
+{
+  return (aNode2->CompareDocumentPosition(*aNode1) &
+    (nsIDOMNode::DOCUMENT_POSITION_PRECEDING |
+     nsIDOMNode::DOCUMENT_POSITION_DISCONNECTED)) ==
+    nsIDOMNode::DOCUMENT_POSITION_PRECEDING;
+}
+
+/* static */
+int32_t
+nsContentUtils::ComparePoints(nsINode* aParent1, int32_t aOffset1,
+                              nsINode* aParent2, int32_t aOffset2,
+                              bool* aDisconnected)
+{
+  if (aParent1 == aParent2) {
+    return aOffset1 < aOffset2 ? -1 :
+           aOffset1 > aOffset2 ? 1 :
+           0;
+  }
+
+  AutoTArray<nsINode*, 32> parents1, parents2;
+  nsINode* node1 = aParent1;
+  nsINode* node2 = aParent2;
+  do {
+    parents1.AppendElement(node1);
+    node1 = node1->GetParentNode();
+  } while (node1);
+  do {
+    parents2.AppendElement(node2);
+    node2 = node2->GetParentNode();
+  } while (node2);
+
+  uint32_t pos1 = parents1.Length() - 1;
+  uint32_t pos2 = parents2.Length() - 1;
+
+  bool disconnected = parents1.ElementAt(pos1) != parents2.ElementAt(pos2);
+  if (aDisconnected) {
+    *aDisconnected = disconnected;
+  }
+  if (disconnected) {
+    NS_ASSERTION(aDisconnected, "unexpected disconnected nodes");
+    return 1;
+  }
+
+  // Find where the parent chains differ
+  nsINode* parent = parents1.ElementAt(pos1);
+  uint32_t len;
+  for (len = std::min(pos1, pos2); len > 0; --len) {
+    nsINode* child1 = parents1.ElementAt(--pos1);
+    nsINode* child2 = parents2.ElementAt(--pos2);
+    if (child1 != child2) {
+      return parent->IndexOf(child1) < parent->IndexOf(child2) ? -1 : 1;
+    }
+    parent = child1;
+  }
+
+
+  // The parent chains never differed, so one of the nodes is an ancestor of
+  // the other
+
+  NS_ASSERTION(!pos1 || !pos2,
+               "should have run out of parent chain for one of the nodes");
+
+  if (!pos1) {
+    nsINode* child2 = parents2.ElementAt(--pos2);
+    return aOffset1 <= parent->IndexOf(child2) ? -1 : 1;
+  }
+
+  nsINode* child1 = parents1.ElementAt(--pos1);
+  return parent->IndexOf(child1) < aOffset2 ? -1 : 1;
+}
+
+/* static */
+int32_t
+nsContentUtils::ComparePoints(nsIDOMNode* aParent1, int32_t aOffset1,
+                              nsIDOMNode* aParent2, int32_t aOffset2,
+                              bool* aDisconnected)
+{
+  nsCOMPtr<nsINode> parent1 = do_QueryInterface(aParent1);
+  nsCOMPtr<nsINode> parent2 = do_QueryInterface(aParent2);
+  NS_ENSURE_TRUE(parent1 && parent2, -1);
+  return ComparePoints(parent1, aOffset1, parent2, aOffset2);
+}
+
+inline bool
+IsCharInSet(const char* aSet,
+            const char16_t aChar)
+{
+  char16_t ch;
+  while ((ch = *aSet)) {
+    if (aChar == char16_t(ch)) {
+      return true;
+    }
+    ++aSet;
+  }
+  return false;
+}
+
+/**
+ * This method strips leading/trailing chars, in given set, from string.
+ */
+
+// static
+const nsDependentSubstring
+nsContentUtils::TrimCharsInSet(const char* aSet,
+                               const nsAString& aValue)
+{
+  nsAString::const_iterator valueCurrent, valueEnd;
+
+  aValue.BeginReading(valueCurrent);
+  aValue.EndReading(valueEnd);
+
+  // Skip characters in the beginning
+  while (valueCurrent != valueEnd) {
+    if (!IsCharInSet(aSet, *valueCurrent)) {
+      break;
+    }
+    ++valueCurrent;
+  }
+
+  if (valueCurrent != valueEnd) {
+    for (;;) {
+      --valueEnd;
+      if (!IsCharInSet(aSet, *valueEnd)) {
+        break;
+      }
+    }
+    ++valueEnd; // Step beyond the last character we want in the value.
+  }
+
+  // valueEnd should point to the char after the last to copy
+  return Substring(valueCurrent, valueEnd);
+}
+
+/**
+ * This method strips leading and trailing whitespace from a string.
+ */
+
+// static
+template<bool IsWhitespace(char16_t)>
+const nsDependentSubstring
+nsContentUtils::TrimWhitespace(const nsAString& aStr, bool aTrimTrailing)
+{
+  nsAString::const_iterator start, end;
+
+  aStr.BeginReading(start);
+  aStr.EndReading(end);
+
+  // Skip whitespace characters in the beginning
+  while (start != end && IsWhitespace(*start)) {
+    ++start;
+  }
+
+  if (aTrimTrailing) {
+    // Skip whitespace characters in the end.
+    while (end != start) {
+      --end;
+
+      if (!IsWhitespace(*end)) {
+        // Step back to the last non-whitespace character.
+        ++end;
+
+        break;
+      }
+    }
+  }
+
+  // Return a substring for the string w/o leading and/or trailing
+  // whitespace
+
+  return Substring(start, end);
+}
+
+// Declaring the templates we are going to use avoid linking issues without
+// inlining the method. Considering there is not so much spaces checking
+// methods we can consider this to be better than inlining.
+template
+const nsDependentSubstring
+nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(const nsAString&, bool);
+template
+const nsDependentSubstring
+nsContentUtils::TrimWhitespace<nsContentUtils::IsHTMLWhitespace>(const nsAString&, bool);
+template
+const nsDependentSubstring
+nsContentUtils::TrimWhitespace<nsContentUtils::IsHTMLWhitespaceOrNBSP>(const nsAString&, bool);
+
+static inline void KeyAppendSep(nsACString& aKey)
+{
+  if (!aKey.IsEmpty()) {
+    aKey.Append('>');
+  }
+}
+
+static inline void KeyAppendString(const nsAString& aString, nsACString& aKey)
+{
+  KeyAppendSep(aKey);
+
+  // Could escape separator here if collisions happen.  > is not a legal char
+  // for a name or type attribute, so we should be safe avoiding that extra work.
+
+  AppendUTF16toUTF8(aString, aKey);
+}
+
+static inline void KeyAppendString(const nsACString& aString, nsACString& aKey)
+{
+  KeyAppendSep(aKey);
+
+  // Could escape separator here if collisions happen.  > is not a legal char
+  // for a name or type attribute, so we should be safe avoiding that extra work.
+
+  aKey.Append(aString);
+}
+
+static inline void KeyAppendInt(int32_t aInt, nsACString& aKey)
+{
+  KeyAppendSep(aKey);
+
+  aKey.Append(nsPrintfCString("%d", aInt));
+}
+
+static inline bool IsAutocompleteOff(const nsIContent* aElement)
+{
+  return aElement->AttrValueIs(kNameSpaceID_None, nsGkAtoms::autocomplete,
+                               NS_LITERAL_STRING("off"), eIgnoreCase);
+}
+
+/*static*/ nsresult
+nsContentUtils::GenerateStateKey(nsIContent* aContent,
+                                 const nsIDocument* aDocument,
+                                 nsACString& aKey)
+{
+  aKey.Truncate();
+
+  uint32_t partID = aDocument ? aDocument->GetPartID() : 0;
+
+  // We must have content if we're not using a special state id
+  NS_ENSURE_TRUE(aContent, NS_ERROR_FAILURE);
+
+  // Don't capture state for anonymous content
+  if (aContent->IsInAnonymousSubtree()) {
+    return NS_OK;
+  }
+
+  if (IsAutocompleteOff(aContent)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIHTMLDocument> htmlDocument =
+    do_QueryInterface(aContent->GetUncomposedDoc());
+
+  KeyAppendInt(partID, aKey);  // first append a partID
+  bool generatedUniqueKey = false;
+
+  if (htmlDocument) {
+    // Flush our content model so it'll be up to date
+    // If this becomes unnecessary and the following line is removed,
+    // please also remove the corresponding flush operation from
+    // nsHtml5TreeBuilderCppSupplement.h. (Look for "See bug 497861." there.)
+    aContent->GetUncomposedDoc()->FlushPendingNotifications(Flush_Content);
+
+    nsContentList *htmlForms = htmlDocument->GetForms();
+    nsContentList *htmlFormControls = htmlDocument->GetFormControls();
+
+    NS_ENSURE_TRUE(htmlForms && htmlFormControls, NS_ERROR_OUT_OF_MEMORY);
+
+    // If we have a form control and can calculate form information, use that
+    // as the key - it is more reliable than just recording position in the
+    // DOM.
+    // XXXbz Is it, really?  We have bugs on this, I think...
+    // Important to have a unique key, and tag/type/name may not be.
+    //
+    // If the control has a form, the format of the key is:
+    // f>type>IndOfFormInDoc>IndOfControlInForm>FormName>name
+    // else:
+    // d>type>IndOfControlInDoc>name
+    //
+    // XXX We don't need to use index if name is there
+    // XXXbz We don't?  Why not?  I don't follow.
+    //
+    nsCOMPtr<nsIFormControl> control(do_QueryInterface(aContent));
+    if (control && htmlFormControls && htmlForms) {
+
+      // Append the control type
+      KeyAppendInt(control->GetType(), aKey);
+
+      // If in a form, add form name / index of form / index in form
+      int32_t index = -1;
+      Element *formElement = control->GetFormElement();
+      if (formElement) {
+        if (IsAutocompleteOff(formElement)) {
+          aKey.Truncate();
+          return NS_OK;
+        }
+
+        KeyAppendString(NS_LITERAL_CSTRING("f"), aKey);
+
+        // Append the index of the form in the document
+        index = htmlForms->IndexOf(formElement, false);
+        if (index <= -1) {
+          //
+          // XXX HACK this uses some state that was dumped into the document
+          // specifically to fix bug 138892.  What we are trying to do is *guess*
+          // which form this control's state is found in, with the highly likely
+          // guess that the highest form parsed so far is the one.
+          // This code should not be on trunk, only branch.
+          //
+          index = htmlDocument->GetNumFormsSynchronous() - 1;
+        }
+        if (index > -1) {
+          KeyAppendInt(index, aKey);
+
+          // Append the index of the control in the form
+          nsCOMPtr<nsIForm> form(do_QueryInterface(formElement));
+          index = form->IndexOfControl(control);
+
+          if (index > -1) {
+            KeyAppendInt(index, aKey);
+            generatedUniqueKey = true;
+          }
+        }
+
+        // Append the form name
+        nsAutoString formName;
+        formElement->GetAttr(kNameSpaceID_None, nsGkAtoms::name, formName);
+        KeyAppendString(formName, aKey);
+
+      } else {
+
+        KeyAppendString(NS_LITERAL_CSTRING("d"), aKey);
+
+        // If not in a form, add index of control in document
+        // Less desirable than indexing by form info.
+
+        // Hash by index of control in doc (we are not in a form)
+        // These are important as they are unique, and type/name may not be.
+
+        // We have to flush sink notifications at this point to make
+        // sure that htmlFormControls is up to date.
+        index = htmlFormControls->IndexOf(aContent, true);
+        if (index > -1) {
+          KeyAppendInt(index, aKey);
+          generatedUniqueKey = true;
+        }
+      }
+
+      // Append the control name
+      nsAutoString name;
+      aContent->GetAttr(kNameSpaceID_None, nsGkAtoms::name, name);
+      KeyAppendString(name, aKey);
+    }
+  }
+
+  if (!generatedUniqueKey) {
+    // Either we didn't have a form control or we aren't in an HTML document so
+    // we can't figure out form info.  Append the tag name if it's an element
+    // to avoid restoring state for one type of element on another type.
+    if (aContent->IsElement()) {
+      KeyAppendString(nsDependentAtomString(aContent->NodeInfo()->NameAtom()),
+                      aKey);
+    }
+    else {
+      // Append a character that is not "d" or "f" to disambiguate from
+      // the case when we were a form control in an HTML document.
+      KeyAppendString(NS_LITERAL_CSTRING("o"), aKey);
+    }
+
+    // Now start at aContent and append the indices of it and all its ancestors
+    // in their containers.  That should at least pin down its position in the
+    // DOM...
+    nsINode* parent = aContent->GetParentNode();
+    nsINode* content = aContent;
+    while (parent) {
+      KeyAppendInt(parent->IndexOf(content), aKey);
+      content = parent;
+      parent = content->GetParentNode();
+    }
+  }
+
+  return NS_OK;
+}
+
+// static
+nsIPrincipal*
+nsContentUtils::SubjectPrincipal()
+{
+  MOZ_ASSERT(IsInitialized());
+  MOZ_ASSERT(NS_IsMainThread());
+  JSContext* cx = GetCurrentJSContext();
+  if (!cx) {
+    MOZ_CRASH("Accessing the Subject Principal without an AutoJSAPI on the stack is forbidden");
+  }
+
+  JSCompartment *compartment = js::GetContextCompartment(cx);
+
+  // When an AutoJSAPI is instantiated, we are in a null compartment until the
+  // first JSAutoCompartment, which is kind of a purgatory as far as permissions
+  // go. It would be nice to just hard-abort if somebody does a security check
+  // in this purgatory zone, but that would be too fragile, since it could be
+  // triggered by random IsCallerChrome() checks 20-levels deep.
+  //
+  // So we want to return _something_ here - and definitely not the System
+  // Principal, since that would make an AutoJSAPI a very dangerous thing to
+  // instantiate.
+  //
+  // The natural thing to return is a null principal. Ideally, we'd return a
+  // different null principal each time, to avoid any unexpected interactions
+  // when the principal accidentally gets inherited somewhere. But
+  // GetSubjectPrincipal doesn't return strong references, so there's no way to
+  // sanely manage the lifetime of multiple null principals.
+  //
+  // So we use a singleton null principal. To avoid it being accidentally
+  // inherited and becoming a "real" subject or object principal, we do a
+  // release-mode assert during compartment creation against using this
+  // principal on an actual global.
+  if (!compartment) {
+    return sNullSubjectPrincipal;
+  }
+
+  JSPrincipals *principals = JS_GetCompartmentPrincipals(compartment);
+  return nsJSPrincipals::get(principals);
+}
+
+// static
+nsIPrincipal*
+nsContentUtils::ObjectPrincipal(JSObject* aObj)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+#ifdef DEBUG
+  JS::AssertObjectBelongsToCurrentThread(aObj);
+#endif
+
+  // This is duplicated from nsScriptSecurityManager. We don't call through there
+  // because the API unnecessarily requires a JSContext for historical reasons.
+  JSCompartment *compartment = js::GetObjectCompartment(aObj);
+  JSPrincipals *principals = JS_GetCompartmentPrincipals(compartment);
+  return nsJSPrincipals::get(principals);
+}
+
+// static
+nsresult
+nsContentUtils::NewURIWithDocumentCharset(nsIURI** aResult,
+                                          const nsAString& aSpec,
+                                          nsIDocument* aDocument,
+                                          nsIURI* aBaseURI)
+{
+  return NS_NewURI(aResult, aSpec,
+                   aDocument ? aDocument->GetDocumentCharacterSet().get() : nullptr,
+                   aBaseURI, sIOService);
+}
+
+// static
+bool
+nsContentUtils::IsCustomElementName(nsIAtom* aName)
+{
+  // A valid custom element name is a sequence of characters name which
+  // must match the PotentialCustomElementName production:
+  // PotentialCustomElementName ::= [a-z] (PCENChar)* '-' (PCENChar)*
+  const char16_t* name = aName->GetUTF16String();
+  uint32_t len = aName->GetLength();
+  bool hasDash = false;
+
+  if (!len || name[0] < 'a' || name[0] > 'z') {
+    return false;
+  }
+
+  uint32_t i = 1;
+  while (i < len) {
+    if (NS_IS_HIGH_SURROGATE(name[i]) && i + 1 < len &&
+        NS_IS_LOW_SURROGATE(name[i + 1])) {
+      // Merged two 16-bit surrogate pairs into code point.
+      char32_t code = SURROGATE_TO_UCS4(name[i], name[i + 1]);
+
+      if (code < 0x10000 || code > 0xEFFFF) {
+        return false;
+      }
+
+      i += 2;
+    } else {
+      if (name[i] == '-') {
+        hasDash = true;
+      }
+
+      if (name[i] != '-' && name[i] != '.' &&
+          name[i] != '_' && name[i] != 0xB7 &&
+         (name[i] < '0' || name[i] > '9') &&
+         (name[i] < 'a' || name[i] > 'z') &&
+         (name[i] < 0xC0 || name[i] > 0xD6) &&
+         (name[i] < 0xF8 || name[i] > 0x37D) &&
+         (name[i] < 0x37F || name[i] > 0x1FFF) &&
+         (name[i] < 0x200C || name[i] > 0x200D) &&
+         (name[i] < 0x203F || name[i] > 0x2040) &&
+         (name[i] < 0x2070 || name[i] > 0x218F) &&
+         (name[i] < 0x2C00 || name[i] > 0x2FEF) &&
+         (name[i] < 0x3001 || name[i] > 0xD7FF) &&
+         (name[i] < 0xF900 || name[i] > 0xFDCF) &&
+         (name[i] < 0xFDF0 || name[i] > 0xFFFD)) {
+        return false;
+      }
+
+      i++;
+    }
+  }
+
+  if (!hasDash) {
+    return false;
+  }
+
+  // The custom element name must not be one of the following values:
+  //  annotation-xml
+  //  color-profile
+  //  font-face
+  //  font-face-src
+  //  font-face-uri
+  //  font-face-format
+  //  font-face-name
+  //  missing-glyph
+  return aName != nsGkAtoms::annotation_xml_ &&
+         aName != nsGkAtoms::colorProfile &&
+         aName != nsGkAtoms::font_face &&
+         aName != nsGkAtoms::font_face_src &&
+         aName != nsGkAtoms::font_face_uri &&
+         aName != nsGkAtoms::font_face_format &&
+         aName != nsGkAtoms::font_face_name &&
+         aName != nsGkAtoms::missingGlyph;
+}
+
+// static
+nsresult
+nsContentUtils::CheckQName(const nsAString& aQualifiedName,
+                           bool aNamespaceAware,
+                           const char16_t** aColon)
+{
+  const char* colon = nullptr;
+  const char16_t* begin = aQualifiedName.BeginReading();
+  const char16_t* end = aQualifiedName.EndReading();
+
+  int result = MOZ_XMLCheckQName(reinterpret_cast<const char*>(begin),
+                                 reinterpret_cast<const char*>(end),
+                                 aNamespaceAware, &colon);
+
+  if (!result) {
+    if (aColon) {
+      *aColon = reinterpret_cast<const char16_t*>(colon);
+    }
+
+    return NS_OK;
+  }
+
+  // MOZ_EXPAT_EMPTY_QNAME || MOZ_EXPAT_INVALID_CHARACTER
+  if (result == (1 << 0) || result == (1 << 1)) {
+    return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
+  }
+
+  return NS_ERROR_DOM_NAMESPACE_ERR;
+}
+
+//static
+nsresult
+nsContentUtils::SplitQName(const nsIContent* aNamespaceResolver,
+                           const nsAFlatString& aQName,
+                           int32_t *aNamespace, nsIAtom **aLocalName)
+{
+  const char16_t* colon;
+  nsresult rv = nsContentUtils::CheckQName(aQName, true, &colon);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (colon) {
+    const char16_t* end;
+    aQName.EndReading(end);
+    nsAutoString nameSpace;
+    rv = aNamespaceResolver->LookupNamespaceURIInternal(Substring(aQName.get(),
+                                                                  colon),
+                                                        nameSpace);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    *aNamespace = NameSpaceManager()->GetNameSpaceID(nameSpace,
+                                                     nsContentUtils::IsChromeDoc(aNamespaceResolver->OwnerDoc()));
+    if (*aNamespace == kNameSpaceID_Unknown)
+      return NS_ERROR_FAILURE;
+
+    *aLocalName = NS_Atomize(Substring(colon + 1, end)).take();
+  }
+  else {
+    *aNamespace = kNameSpaceID_None;
+    *aLocalName = NS_Atomize(aQName).take();
+  }
+  NS_ENSURE_TRUE(aLocalName, NS_ERROR_OUT_OF_MEMORY);
+  return NS_OK;
+}
+
+// static
+nsresult
+nsContentUtils::GetNodeInfoFromQName(const nsAString& aNamespaceURI,
+                                     const nsAString& aQualifiedName,
+                                     nsNodeInfoManager* aNodeInfoManager,
+                                     uint16_t aNodeType,
+                                     mozilla::dom::NodeInfo** aNodeInfo)
+{
+  const nsAFlatString& qName = PromiseFlatString(aQualifiedName);
+  const char16_t* colon;
+  nsresult rv = nsContentUtils::CheckQName(qName, true, &colon);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int32_t nsID;
+  sNameSpaceManager->RegisterNameSpace(aNamespaceURI, nsID);
+  if (colon) {
+    const char16_t* end;
+    qName.EndReading(end);
+
+    nsCOMPtr<nsIAtom> prefix = NS_Atomize(Substring(qName.get(), colon));
+
+    rv = aNodeInfoManager->GetNodeInfo(Substring(colon + 1, end), prefix,
+                                       nsID, aNodeType, aNodeInfo);
+  }
+  else {
+    rv = aNodeInfoManager->GetNodeInfo(aQualifiedName, nullptr, nsID,
+                                       aNodeType, aNodeInfo);
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return nsContentUtils::IsValidNodeName((*aNodeInfo)->NameAtom(),
+                                         (*aNodeInfo)->GetPrefixAtom(),
+                                         (*aNodeInfo)->NamespaceID()) ?
+         NS_OK : NS_ERROR_DOM_NAMESPACE_ERR;
+}
+
+// static
+void
+nsContentUtils::SplitExpatName(const char16_t *aExpatName, nsIAtom **aPrefix,
+                               nsIAtom **aLocalName, int32_t* aNameSpaceID)
+{
+  /**
+   *  Expat can send the following:
+   *    localName
+   *    namespaceURI<separator>localName
+   *    namespaceURI<separator>localName<separator>prefix
+   *
+   *  and we use 0xFFFF for the <separator>.
+   *
+   */
+
+  const char16_t *uriEnd = nullptr;
+  const char16_t *nameEnd = nullptr;
+  const char16_t *pos;
+  for (pos = aExpatName; *pos; ++pos) {
+    if (*pos == 0xFFFF) {
+      if (uriEnd) {
+        nameEnd = pos;
+      }
+      else {
+        uriEnd = pos;
+      }
+    }
+  }
+
+  const char16_t *nameStart;
+  if (uriEnd) {
+    if (sNameSpaceManager) {
+      sNameSpaceManager->RegisterNameSpace(nsDependentSubstring(aExpatName,
+                                                                uriEnd),
+                                           *aNameSpaceID);
+    }
+    else {
+      *aNameSpaceID = kNameSpaceID_Unknown;
+    }
+
+    nameStart = (uriEnd + 1);
+    if (nameEnd)  {
+      const char16_t *prefixStart = nameEnd + 1;
+      *aPrefix = NS_Atomize(Substring(prefixStart, pos)).take();
+    }
+    else {
+      nameEnd = pos;
+      *aPrefix = nullptr;
+    }
+  }
+  else {
+    *aNameSpaceID = kNameSpaceID_None;
+    nameStart = aExpatName;
+    nameEnd = pos;
+    *aPrefix = nullptr;
+  }
+  *aLocalName = NS_Atomize(Substring(nameStart, nameEnd)).take();
+}
+
+// static
+nsPresContext*
+nsContentUtils::GetContextForContent(const nsIContent* aContent)
+{
+  nsIDocument* doc = aContent->GetComposedDoc();
+  if (doc) {
+    nsIPresShell *presShell = doc->GetShell();
+    if (presShell) {
+      return presShell->GetPresContext();
+    }
+  }
+  return nullptr;
+}
+
+// static
+bool
+nsContentUtils::CanLoadImage(nsIURI* aURI, nsISupports* aContext,
+                             nsIDocument* aLoadingDocument,
+                             nsIPrincipal* aLoadingPrincipal,
+                             int16_t* aImageBlockingStatus,
+                             uint32_t aContentType)
+{
+  NS_PRECONDITION(aURI, "Must have a URI");
+  NS_PRECONDITION(aLoadingDocument, "Must have a document");
+  NS_PRECONDITION(aLoadingPrincipal, "Must have a loading principal");
+
+  nsresult rv;
+
+  uint32_t appType = nsIDocShell::APP_TYPE_UNKNOWN;
+
+  {
+    nsCOMPtr<nsIDocShellTreeItem> docShellTreeItem = aLoadingDocument->GetDocShell();
+    if (docShellTreeItem) {
+      nsCOMPtr<nsIDocShellTreeItem> root;
+      docShellTreeItem->GetRootTreeItem(getter_AddRefs(root));
+
+      nsCOMPtr<nsIDocShell> docShell(do_QueryInterface(root));
+
+      if (!docShell || NS_FAILED(docShell->GetAppType(&appType))) {
+        appType = nsIDocShell::APP_TYPE_UNKNOWN;
+      }
+    }
+  }
+
+  if (appType != nsIDocShell::APP_TYPE_EDITOR) {
+    // Editor apps get special treatment here, editors can load images
+    // from anywhere.  This allows editor to insert images from file://
+    // into documents that are being edited.
+    rv = sSecurityManager->
+      CheckLoadURIWithPrincipal(aLoadingPrincipal, aURI,
+                                nsIScriptSecurityManager::ALLOW_CHROME);
+    if (NS_FAILED(rv)) {
+      if (aImageBlockingStatus) {
+        // Reject the request itself, not all requests to the relevant
+        // server...
+        *aImageBlockingStatus = nsIContentPolicy::REJECT_REQUEST;
+      }
+      return false;
+    }
+  }
+
+  int16_t decision = nsIContentPolicy::ACCEPT;
+
+  rv = NS_CheckContentLoadPolicy(aContentType,
+                                 aURI,
+                                 aLoadingPrincipal,
+                                 aContext,
+                                 EmptyCString(), //mime guess
+                                 nullptr,         //extra
+                                 &decision,
+                                 GetContentPolicy(),
+                                 sSecurityManager);
+
+  if (aImageBlockingStatus) {
+    *aImageBlockingStatus =
+      NS_FAILED(rv) ? nsIContentPolicy::REJECT_REQUEST : decision;
+  }
+  return NS_FAILED(rv) ? false : NS_CP_ACCEPTED(decision);
+}
+
+// static
+mozilla::PrincipalOriginAttributes
+nsContentUtils::GetOriginAttributes(nsIDocument* aDocument)
+{
+  if (!aDocument) {
+    return mozilla::PrincipalOriginAttributes();
+  }
+
+  nsCOMPtr<nsILoadGroup> loadGroup = aDocument->GetDocumentLoadGroup();
+  if (loadGroup) {
+    return GetOriginAttributes(loadGroup);
+  }
+
+  mozilla::PrincipalOriginAttributes attrs;
+  mozilla::NeckoOriginAttributes nattrs;
+  nsCOMPtr<nsIChannel> channel = aDocument->GetChannel();
+  if (channel && NS_GetOriginAttributes(channel, nattrs)) {
+    attrs.InheritFromNecko(nattrs);
+  }
+  return attrs;
+}
+
+// static
+mozilla::PrincipalOriginAttributes
+nsContentUtils::GetOriginAttributes(nsILoadGroup* aLoadGroup)
+{
+  if (!aLoadGroup) {
+    return mozilla::PrincipalOriginAttributes();
+  }
+  mozilla::PrincipalOriginAttributes attrs;
+  mozilla::DocShellOriginAttributes dsattrs;
+  nsCOMPtr<nsIInterfaceRequestor> callbacks;
+  aLoadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
+  if (callbacks) {
+    nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(callbacks);
+    if (loadContext && loadContext->GetOriginAttributes(dsattrs)) {
+      attrs.InheritFromDocShellToDoc(dsattrs, nullptr);
+    }
+  }
+  return attrs;
+}
+
+// static
+bool
+nsContentUtils::IsInPrivateBrowsing(nsIDocument* aDoc)
+{
+  if (!aDoc) {
+    return false;
+  }
+
+  nsCOMPtr<nsILoadGroup> loadGroup = aDoc->GetDocumentLoadGroup();
+  if (loadGroup) {
+    return IsInPrivateBrowsing(loadGroup);
+  }
+
+  nsCOMPtr<nsIChannel> channel = aDoc->GetChannel();
+  return channel && NS_UsePrivateBrowsing(channel);
+}
+
+// static
+bool
+nsContentUtils::IsInPrivateBrowsing(nsILoadGroup* aLoadGroup)
+{
+  if (!aLoadGroup) {
+    return false;
+  }
+  bool isPrivate = false;
+  nsCOMPtr<nsIInterfaceRequestor> callbacks;
+  aLoadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
+  if (callbacks) {
+    nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(callbacks);
+    isPrivate = loadContext && loadContext->UsePrivateBrowsing();
+  }
+  return isPrivate;
+}
+
+bool
+nsContentUtils::DocumentInactiveForImageLoads(nsIDocument* aDocument)
+{
+  if (aDocument && !IsChromeDoc(aDocument) && !aDocument->IsResourceDoc()) {
+    nsCOMPtr<nsPIDOMWindowInner> win =
+      do_QueryInterface(aDocument->GetScopeObject());
+    return !win || !win->GetDocShell();
+  }
+  return false;
+}
+
+imgLoader*
+nsContentUtils::GetImgLoaderForDocument(nsIDocument* aDoc)
+{
+  NS_ENSURE_TRUE(!DocumentInactiveForImageLoads(aDoc), nullptr);
+
+  if (!aDoc) {
+    return imgLoader::NormalLoader();
+  }
+  bool isPrivate = IsInPrivateBrowsing(aDoc);
+  return isPrivate ? imgLoader::PrivateBrowsingLoader()
+                   : imgLoader::NormalLoader();
+}
+
+// static
+imgLoader*
+nsContentUtils::GetImgLoaderForChannel(nsIChannel* aChannel,
+                                       nsIDocument* aContext)
+{
+  NS_ENSURE_TRUE(!DocumentInactiveForImageLoads(aContext), nullptr);
+
+  if (!aChannel) {
+    return imgLoader::NormalLoader();
+  }
+  nsCOMPtr<nsILoadContext> context;
+  NS_QueryNotificationCallbacks(aChannel, context);
+  return context && context->UsePrivateBrowsing() ?
+                      imgLoader::PrivateBrowsingLoader() :
+                      imgLoader::NormalLoader();
+}
+
+// static
+bool
+nsContentUtils::IsImageInCache(nsIURI* aURI, nsIDocument* aDocument)
+{
+    imgILoader* loader = GetImgLoaderForDocument(aDocument);
+    nsCOMPtr<imgICache> cache = do_QueryInterface(loader);
+
+    // If something unexpected happened we return false, otherwise if props
+    // is set, the image is cached and we return true
+    nsCOMPtr<nsIProperties> props;
+    nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(aDocument);
+    nsresult rv = cache->FindEntryProperties(aURI, domDoc, getter_AddRefs(props));
+    return (NS_SUCCEEDED(rv) && props);
+}
+
+// static
+nsresult
+nsContentUtils::LoadImage(nsIURI* aURI, nsINode* aContext,
+                          nsIDocument* aLoadingDocument,
+                          nsIPrincipal* aLoadingPrincipal, nsIURI* aReferrer,
+                          net::ReferrerPolicy aReferrerPolicy,
+                          imgINotificationObserver* aObserver, int32_t aLoadFlags,
+                          const nsAString& initiatorType,
+                          imgRequestProxy** aRequest,
+                          uint32_t aContentPolicyType)
+{
+  NS_PRECONDITION(aURI, "Must have a URI");
+  NS_PRECONDITION(aContext, "Must have a context");
+  NS_PRECONDITION(aLoadingDocument, "Must have a document");
+  NS_PRECONDITION(aLoadingPrincipal, "Must have a principal");
+  NS_PRECONDITION(aRequest, "Null out param");
+
+  imgLoader* imgLoader = GetImgLoaderForDocument(aLoadingDocument);
+  if (!imgLoader) {
+    // nothing we can do here
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsILoadGroup> loadGroup = aLoadingDocument->GetDocumentLoadGroup();
+
+  nsIURI *documentURI = aLoadingDocument->GetDocumentURI();
+
+  NS_ASSERTION(loadGroup || IsFontTableURI(documentURI),
+               "Could not get loadgroup; onload may fire too early");
+
+  // Make the URI immutable so people won't change it under us
+  NS_TryToSetImmutable(aURI);
+
+  // XXXbz using "documentURI" for the initialDocumentURI is not quite
+  // right, but the best we can do here...
+  return imgLoader->LoadImage(aURI,                 /* uri to load */
+                              documentURI,          /* initialDocumentURI */
+                              aReferrer,            /* referrer */
+                              aReferrerPolicy,      /* referrer policy */
+                              aLoadingPrincipal,    /* loading principal */
+                              loadGroup,            /* loadgroup */
+                              aObserver,            /* imgINotificationObserver */
+                              aContext,             /* loading context */
+                              aLoadingDocument,     /* uniquification key */
+                              aLoadFlags,           /* load flags */
+                              nullptr,              /* cache key */
+                              aContentPolicyType,   /* content policy type */
+                              initiatorType,        /* the load initiator */
+                              aRequest);
+}
+
+// static
+already_AddRefed<imgIContainer>
+nsContentUtils::GetImageFromContent(nsIImageLoadingContent* aContent,
+                                    imgIRequest **aRequest)
+{
+  if (aRequest) {
+    *aRequest = nullptr;
+  }
+
+  NS_ENSURE_TRUE(aContent, nullptr);
+
+  nsCOMPtr<imgIRequest> imgRequest;
+  aContent->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
+                      getter_AddRefs(imgRequest));
+  if (!imgRequest) {
+    return nullptr;
+  }
+
+  nsCOMPtr<imgIContainer> imgContainer;
+  imgRequest->GetImage(getter_AddRefs(imgContainer));
+
+  if (!imgContainer) {
+    return nullptr;
+  }
+
+  if (aRequest) {
+    imgRequest.swap(*aRequest);
+  }
+
+  return imgContainer.forget();
+}
+
+//static
+already_AddRefed<imgRequestProxy>
+nsContentUtils::GetStaticRequest(imgRequestProxy* aRequest)
+{
+  NS_ENSURE_TRUE(aRequest, nullptr);
+  RefPtr<imgRequestProxy> retval;
+  aRequest->GetStaticRequest(getter_AddRefs(retval));
+  return retval.forget();
+}
+
+// static
+bool
+nsContentUtils::ContentIsDraggable(nsIContent* aContent)
+{
+  nsCOMPtr<nsIDOMHTMLElement> htmlElement = do_QueryInterface(aContent);
+  if (htmlElement) {
+    bool draggable = false;
+    htmlElement->GetDraggable(&draggable);
+    if (draggable)
+      return true;
+
+    if (aContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::draggable,
+                              nsGkAtoms::_false, eIgnoreCase))
+      return false;
+  }
+
+  // special handling for content area image and link dragging
+  return IsDraggableImage(aContent) || IsDraggableLink(aContent);
+}
+
+// static
+bool
+nsContentUtils::IsDraggableImage(nsIContent* aContent)
+{
+  NS_PRECONDITION(aContent, "Must have content node to test");
+
+  nsCOMPtr<nsIImageLoadingContent> imageContent(do_QueryInterface(aContent));
+  if (!imageContent) {
+    return false;
+  }
+
+  nsCOMPtr<imgIRequest> imgRequest;
+  imageContent->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
+                           getter_AddRefs(imgRequest));
+
+  // XXXbz It may be draggable even if the request resulted in an error.  Why?
+  // Not sure; that's what the old nsContentAreaDragDrop/nsFrame code did.
+  return imgRequest != nullptr;
+}
+
+// static
+bool
+nsContentUtils::IsDraggableLink(const nsIContent* aContent) {
+  nsCOMPtr<nsIURI> absURI;
+  return aContent->IsLink(getter_AddRefs(absURI));
+}
+
+// static
+nsresult
+nsContentUtils::NameChanged(mozilla::dom::NodeInfo* aNodeInfo, nsIAtom* aName,
+                            mozilla::dom::NodeInfo** aResult)
+{
+  nsNodeInfoManager *niMgr = aNodeInfo->NodeInfoManager();
+
+  *aResult = niMgr->GetNodeInfo(aName, aNodeInfo->GetPrefixAtom(),
+                                aNodeInfo->NamespaceID(),
+                                aNodeInfo->NodeType(),
+                                aNodeInfo->GetExtraName()).take();
+  return NS_OK;
+}
+
+
+static bool
+TestSitePerm(nsIPrincipal* aPrincipal, const char* aType, uint32_t aPerm, bool aExactHostMatch)
+{
+  if (!aPrincipal) {
+    // We always deny (i.e. don't allow) the permission if we don't have a
+    // principal.
+    return aPerm != nsIPermissionManager::ALLOW_ACTION;
+  }
+
+  nsCOMPtr<nsIPermissionManager> permMgr = services::GetPermissionManager();
+  NS_ENSURE_TRUE(permMgr, false);
+
+  uint32_t perm;
+  nsresult rv;
+  if (aExactHostMatch) {
+    rv = permMgr->TestExactPermissionFromPrincipal(aPrincipal, aType, &perm);
+  } else {
+    rv = permMgr->TestPermissionFromPrincipal(aPrincipal, aType, &perm);
+  }
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return perm == aPerm;
+}
+
+bool
+nsContentUtils::IsSitePermAllow(nsIPrincipal* aPrincipal, const char* aType)
+{
+  return TestSitePerm(aPrincipal, aType, nsIPermissionManager::ALLOW_ACTION, false);
+}
+
+bool
+nsContentUtils::IsSitePermDeny(nsIPrincipal* aPrincipal, const char* aType)
+{
+  return TestSitePerm(aPrincipal, aType, nsIPermissionManager::DENY_ACTION, false);
+}
+
+bool
+nsContentUtils::IsExactSitePermAllow(nsIPrincipal* aPrincipal, const char* aType)
+{
+  return TestSitePerm(aPrincipal, aType, nsIPermissionManager::ALLOW_ACTION, true);
+}
+
+bool
+nsContentUtils::IsExactSitePermDeny(nsIPrincipal* aPrincipal, const char* aType)
+{
+  return TestSitePerm(aPrincipal, aType, nsIPermissionManager::DENY_ACTION, true);
+}
+
+static const char *gEventNames[] = {"event"};
+static const char *gSVGEventNames[] = {"evt"};
+// for b/w compat, the first name to onerror is still 'event', even though it
+// is actually the error message
+static const char *gOnErrorNames[] = {"event", "source", "lineno",
+                                      "colno", "error"};
+
+// static
+void
+nsContentUtils::GetEventArgNames(int32_t aNameSpaceID,
+                                 nsIAtom *aEventName,
+                                 bool aIsForWindow,
+                                 uint32_t *aArgCount,
+                                 const char*** aArgArray)
+{
+#define SET_EVENT_ARG_NAMES(names) \
+    *aArgCount = sizeof(names)/sizeof(names[0]); \
+    *aArgArray = names;
+
+  // JSEventHandler is what does the arg magic for onerror, and it does
+  // not seem to take the namespace into account.  So we let onerror in all
+  // namespaces get the 3 arg names.
+  if (aEventName == nsGkAtoms::onerror && aIsForWindow) {
+    SET_EVENT_ARG_NAMES(gOnErrorNames);
+  } else if (aNameSpaceID == kNameSpaceID_SVG) {
+    SET_EVENT_ARG_NAMES(gSVGEventNames);
+  } else {
+    SET_EVENT_ARG_NAMES(gEventNames);
+  }
+}
+
+static const char gPropertiesFiles[nsContentUtils::PropertiesFile_COUNT][56] = {
+  // Must line up with the enum values in |PropertiesFile| enum.
+  "chrome://global/locale/css.properties",
+  "chrome://global/locale/xbl.properties",
+  "chrome://global/locale/xul.properties",
+  "chrome://global/locale/layout_errors.properties",
+  "chrome://global/locale/layout/HtmlForm.properties",
+  "chrome://global/locale/printing.properties",
+  "chrome://global/locale/dom/dom.properties",
+  "chrome://global/locale/layout/htmlparser.properties",
+  "chrome://global/locale/svg/svg.properties",
+  "chrome://branding/locale/brand.properties",
+  "chrome://global/locale/commonDialogs.properties",
+  "chrome://global/locale/mathml/mathml.properties",
+  "chrome://global/locale/security/security.properties",
+  "chrome://necko/locale/necko.properties"
+};
+
+/* static */ nsresult
+nsContentUtils::EnsureStringBundle(PropertiesFile aFile)
+{
+  if (!sStringBundles[aFile]) {
+    if (!sStringBundleService) {
+      nsresult rv =
+        CallGetService(NS_STRINGBUNDLE_CONTRACTID, &sStringBundleService);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    nsIStringBundle *bundle;
+    nsresult rv =
+      sStringBundleService->CreateBundle(gPropertiesFiles[aFile], &bundle);
+    NS_ENSURE_SUCCESS(rv, rv);
+    sStringBundles[aFile] = bundle; // transfer ownership
+  }
+  return NS_OK;
+}
+
+/* static */
+nsresult nsContentUtils::GetLocalizedString(PropertiesFile aFile,
+                                            const char* aKey,
+                                            nsXPIDLString& aResult)
+{
+  nsresult rv = EnsureStringBundle(aFile);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsIStringBundle *bundle = sStringBundles[aFile];
+
+  return bundle->GetStringFromName(NS_ConvertASCIItoUTF16(aKey).get(),
+                                   getter_Copies(aResult));
+}
+
+/* static */
+nsresult nsContentUtils::FormatLocalizedString(PropertiesFile aFile,
+                                               const char* aKey,
+                                               const char16_t **aParams,
+                                               uint32_t aParamsLength,
+                                               nsXPIDLString& aResult)
+{
+  nsresult rv = EnsureStringBundle(aFile);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsIStringBundle *bundle = sStringBundles[aFile];
+
+  return bundle->FormatStringFromName(NS_ConvertASCIItoUTF16(aKey).get(),
+                                      aParams, aParamsLength,
+                                      getter_Copies(aResult));
+}
+
+/* static */
+nsresult nsContentUtils::FormatLocalizedString(
+                                          PropertiesFile aFile,
+                                          const char* aKey,
+                                          const nsTArray<nsString>& aParamArray,
+                                          nsXPIDLString& aResult)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  UniquePtr<const char16_t*[]> params;
+  uint32_t paramsLength = aParamArray.Length();
+  if (paramsLength > 0) {
+    params = MakeUnique<const char16_t*[]>(paramsLength);
+    for (uint32_t i = 0; i < paramsLength; ++i) {
+      params[i] = aParamArray[i].get();
+    }
+  }
+  return FormatLocalizedString(aFile, aKey, params.get(), paramsLength,
+                               aResult);
+}
+
+
+/* static */ void
+nsContentUtils::LogSimpleConsoleError(const nsAString& aErrorText,
+                                      const char * classification)
+{
+  nsCOMPtr<nsIScriptError> scriptError =
+    do_CreateInstance(NS_SCRIPTERROR_CONTRACTID);
+  if (scriptError) {
+    nsCOMPtr<nsIConsoleService> console =
+      do_GetService(NS_CONSOLESERVICE_CONTRACTID);
+    if (console && NS_SUCCEEDED(scriptError->Init(aErrorText, EmptyString(),
+                                                  EmptyString(), 0, 0,
+                                                  nsIScriptError::errorFlag,
+                                                  classification))) {
+      console->LogMessage(scriptError);
+    }
+  }
+}
+
+/* static */ nsresult
+nsContentUtils::ReportToConsole(uint32_t aErrorFlags,
+                                const nsACString& aCategory,
+                                const nsIDocument* aDocument,
+                                PropertiesFile aFile,
+                                const char *aMessageName,
+                                const char16_t **aParams,
+                                uint32_t aParamsLength,
+                                nsIURI* aURI,
+                                const nsAFlatString& aSourceLine,
+                                uint32_t aLineNumber,
+                                uint32_t aColumnNumber)
+{
+  NS_ASSERTION((aParams && aParamsLength) || (!aParams && !aParamsLength),
+               "Supply either both parameters and their number or no"
+               "parameters and 0.");
+
+  nsresult rv;
+  nsXPIDLString errorText;
+  if (aParams) {
+    rv = FormatLocalizedString(aFile, aMessageName, aParams, aParamsLength,
+                               errorText);
+  }
+  else {
+    rv = GetLocalizedString(aFile, aMessageName, errorText);
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return ReportToConsoleNonLocalized(errorText, aErrorFlags, aCategory,
+                                     aDocument, aURI, aSourceLine,
+                                     aLineNumber, aColumnNumber);
+}
+
+
+/* static */ nsresult
+nsContentUtils::ReportToConsoleNonLocalized(const nsAString& aErrorText,
+                                            uint32_t aErrorFlags,
+                                            const nsACString& aCategory,
+                                            const nsIDocument* aDocument,
+                                            nsIURI* aURI,
+                                            const nsAFlatString& aSourceLine,
+                                            uint32_t aLineNumber,
+                                            uint32_t aColumnNumber,
+                                            MissingErrorLocationMode aLocationMode)
+{
+  uint64_t innerWindowID = 0;
+  if (aDocument) {
+    if (!aURI) {
+      aURI = aDocument->GetDocumentURI();
+    }
+    innerWindowID = aDocument->InnerWindowID();
+  }
+
+  nsresult rv;
+  if (!sConsoleService) { // only need to bother null-checking here
+    rv = CallGetService(NS_CONSOLESERVICE_CONTRACTID, &sConsoleService);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  nsAutoCString spec;
+  if (!aLineNumber && aLocationMode == eUSE_CALLING_LOCATION) {
+    JSContext *cx = GetCurrentJSContext();
+    if (cx) {
+      nsJSUtils::GetCallingLocation(cx, spec, &aLineNumber, &aColumnNumber);
+    }
+  }
+  if (spec.IsEmpty() && aURI) {
+    spec = aURI->GetSpecOrDefault();
+  }
+
+  nsCOMPtr<nsIScriptError> errorObject =
+      do_CreateInstance(NS_SCRIPTERROR_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = errorObject->InitWithWindowID(aErrorText,
+                                     NS_ConvertUTF8toUTF16(spec), // file name
+                                     aSourceLine,
+                                     aLineNumber, aColumnNumber,
+                                     aErrorFlags, aCategory,
+                                     innerWindowID);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return sConsoleService->LogMessage(errorObject);
+}
+
+void
+nsContentUtils::LogMessageToConsole(const char* aMsg)
+{
+  if (!sConsoleService) { // only need to bother null-checking here
+    CallGetService(NS_CONSOLESERVICE_CONTRACTID, &sConsoleService);
+    if (!sConsoleService) {
+      return;
+    }
+  }
+  sConsoleService->LogStringMessage(NS_ConvertUTF8toUTF16(aMsg).get());
+}
+
+bool
+nsContentUtils::IsChromeDoc(nsIDocument *aDocument)
+{
+  if (!aDocument) {
+    return false;
+  }
+  return aDocument->NodePrincipal() == sSystemPrincipal;
+}
+
+bool
+nsContentUtils::IsChildOfSameType(nsIDocument* aDoc)
+{
+  nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(aDoc->GetDocShell());
+  nsCOMPtr<nsIDocShellTreeItem> sameTypeParent;
+  if (docShellAsItem) {
+    docShellAsItem->GetSameTypeParent(getter_AddRefs(sameTypeParent));
+  }
+  return sameTypeParent != nullptr;
+}
+
+bool
+nsContentUtils::IsScriptType(const nsACString& aContentType)
+{
+  // NOTE: if you add a type here, add it to the CONTENTDLF_CATEGORIES
+  // define in nsContentDLF.h as well.
+  return aContentType.EqualsLiteral(APPLICATION_JAVASCRIPT) ||
+         aContentType.EqualsLiteral(APPLICATION_XJAVASCRIPT) ||
+         aContentType.EqualsLiteral(TEXT_ECMASCRIPT) ||
+         aContentType.EqualsLiteral(APPLICATION_ECMASCRIPT) ||
+         aContentType.EqualsLiteral(TEXT_JAVASCRIPT) ||
+         aContentType.EqualsLiteral(APPLICATION_JSON) ||
+         aContentType.EqualsLiteral(TEXT_JSON);
+}
+
+bool
+nsContentUtils::IsPlainTextType(const nsACString& aContentType)
+{
+  // NOTE: if you add a type here, add it to the CONTENTDLF_CATEGORIES
+  // define in nsContentDLF.h as well.
+  return aContentType.EqualsLiteral(TEXT_PLAIN) ||
+         aContentType.EqualsLiteral(TEXT_CSS) ||
+         aContentType.EqualsLiteral(TEXT_CACHE_MANIFEST) ||
+         aContentType.EqualsLiteral(TEXT_VTT) ||
+         IsScriptType(aContentType);
+}
+
+bool
+nsContentUtils::GetWrapperSafeScriptFilename(nsIDocument* aDocument,
+                                             nsIURI* aURI,
+                                             nsACString& aScriptURI,
+                                             nsresult* aRv)
+{
+  MOZ_ASSERT(aRv);
+  bool scriptFileNameModified = false;
+  *aRv = NS_OK;
+
+  *aRv = aURI->GetSpec(aScriptURI);
+  NS_ENSURE_SUCCESS(*aRv, false);
+
+  if (IsChromeDoc(aDocument)) {
+    nsCOMPtr<nsIChromeRegistry> chromeReg =
+      mozilla::services::GetChromeRegistryService();
+
+    if (!chromeReg) {
+      // If we're running w/o a chrome registry we won't modify any
+      // script file names.
+
+      return scriptFileNameModified;
+    }
+
+    bool docWrappersEnabled =
+      chromeReg->WrappersEnabled(aDocument->GetDocumentURI());
+
+    bool uriWrappersEnabled = chromeReg->WrappersEnabled(aURI);
+
+    nsIURI *docURI = aDocument->GetDocumentURI();
+
+    if (docURI && docWrappersEnabled && !uriWrappersEnabled) {
+      // aURI is a script from a URL that doesn't get wrapper
+      // automation. aDocument is a chrome document that does get
+      // wrapper automation. Prepend the chrome document's URI
+      // followed by the string " -> " to the URI of the script we're
+      // loading here so that script in that URI gets the same wrapper
+      // automation that the chrome document expects.
+      nsAutoCString spec;
+      *aRv = docURI->GetSpec(spec);
+      if (NS_WARN_IF(NS_FAILED(*aRv))) {
+        return false;
+      }
+
+      spec.AppendLiteral(" -> ");
+      spec.Append(aScriptURI);
+
+      aScriptURI = spec;
+
+      scriptFileNameModified = true;
+    }
+  }
+
+  return scriptFileNameModified;
+}
+
+// static
+bool
+nsContentUtils::IsInChromeDocshell(nsIDocument *aDocument)
+{
+  if (!aDocument) {
+    return false;
+  }
+
+  if (aDocument->GetDisplayDocument()) {
+    return IsInChromeDocshell(aDocument->GetDisplayDocument());
+  }
+
+  nsCOMPtr<nsIDocShellTreeItem> docShell = aDocument->GetDocShell();
+  if (!docShell) {
+    return false;
+  }
+
+  return docShell->ItemType() == nsIDocShellTreeItem::typeChrome;
+}
+
+// static
+nsIContentPolicy*
+nsContentUtils::GetContentPolicy()
+{
+  if (!sTriedToGetContentPolicy) {
+    CallGetService(NS_CONTENTPOLICY_CONTRACTID, &sContentPolicyService);
+    // It's OK to not have a content policy service
+    sTriedToGetContentPolicy = true;
+  }
+
+  return sContentPolicyService;
+}
+
+// static
+bool
+nsContentUtils::IsEventAttributeName(nsIAtom* aName, int32_t aType)
+{
+  const char16_t* name = aName->GetUTF16String();
+  if (name[0] != 'o' || name[1] != 'n')
+    return false;
+
+  EventNameMapping mapping;
+  return (sAtomEventTable->Get(aName, &mapping) && mapping.mType & aType);
+}
+
+// static
+EventMessage
+nsContentUtils::GetEventMessage(nsIAtom* aName)
+{
+  if (aName) {
+    EventNameMapping mapping;
+    if (sAtomEventTable->Get(aName, &mapping)) {
+      return mapping.mMessage;
+    }
+  }
+
+  return eUnidentifiedEvent;
+}
+
+// static
+mozilla::EventClassID
+nsContentUtils::GetEventClassID(const nsAString& aName)
+{
+  EventNameMapping mapping;
+  if (sStringEventTable->Get(aName, &mapping))
+    return mapping.mEventClassID;
+
+  return eBasicEventClass;
+}
+
+nsIAtom*
+nsContentUtils::GetEventMessageAndAtom(const nsAString& aName,
+                                       mozilla::EventClassID aEventClassID,
+                                       EventMessage* aEventMessage)
+{
+  EventNameMapping mapping;
+  if (sStringEventTable->Get(aName, &mapping)) {
+    *aEventMessage =
+      mapping.mEventClassID == aEventClassID ? mapping.mMessage :
+                                               eUnidentifiedEvent;
+    return mapping.mAtom;
+  }
+
+  // If we have cached lots of user defined event names, clear some of them.
+  if (sUserDefinedEvents->Count() > 127) {
+    while (sUserDefinedEvents->Count() > 64) {
+      nsIAtom* first = sUserDefinedEvents->ObjectAt(0);
+      sStringEventTable->Remove(Substring(nsDependentAtomString(first), 2));
+      sUserDefinedEvents->RemoveObjectAt(0);
+    }
+  }
+
+  *aEventMessage = eUnidentifiedEvent;
+  nsCOMPtr<nsIAtom> atom = NS_Atomize(NS_LITERAL_STRING("on") + aName);
+  sUserDefinedEvents->AppendObject(atom);
+  mapping.mAtom = atom;
+  mapping.mMessage = eUnidentifiedEvent;
+  mapping.mType = EventNameType_None;
+  mapping.mEventClassID = eBasicEventClass;
+  // This is a slow hashtable call, but at least we cache the result for the
+  // following calls. Because GetEventMessageAndAtomForListener utilizes
+  // sStringEventTable, it needs to know in which cases sStringEventTable
+  // doesn't contain the information it needs so that it can use
+  // sAtomEventTable instead.
+  mapping.mMaybeSpecialSVGorSMILEvent =
+    GetEventMessage(atom) != eUnidentifiedEvent;
+  sStringEventTable->Put(aName, mapping);
+  return mapping.mAtom;
+}
+
+// static
+EventMessage
+nsContentUtils::GetEventMessageAndAtomForListener(const nsAString& aName,
+                                                  nsIAtom** aOnName)
+{
+  // Because of SVG/SMIL sStringEventTable contains a subset of the event names
+  // comparing to the sAtomEventTable. However, usually sStringEventTable
+  // contains the information we need, so in order to reduce hashtable
+  // lookups, start from it.
+  EventNameMapping mapping;
+  EventMessage msg = eUnidentifiedEvent;
+  nsCOMPtr<nsIAtom> atom;
+  if (sStringEventTable->Get(aName, &mapping)) {
+    if (mapping.mMaybeSpecialSVGorSMILEvent) {
+      // Try the atom version so that we should get the right message for
+      // SVG/SMIL.
+      atom = NS_Atomize(NS_LITERAL_STRING("on") + aName);
+      msg = GetEventMessage(atom);
+    } else {
+      atom = mapping.mAtom;
+      msg = mapping.mMessage;
+    }
+    atom.forget(aOnName);
+    return msg;
+  }
+
+  // GetEventMessageAndAtom will cache the event type for the future usage...
+  GetEventMessageAndAtom(aName, eBasicEventClass, &msg);
+
+  // ...and then call this method recursively to get the message and atom from
+  // now updated sStringEventTable.
+  return GetEventMessageAndAtomForListener(aName, aOnName);
+}
+
+static
+nsresult GetEventAndTarget(nsIDocument* aDoc, nsISupports* aTarget,
+                           const nsAString& aEventName,
+                           bool aCanBubble, bool aCancelable,
+                           bool aTrusted, nsIDOMEvent** aEvent,
+                           EventTarget** aTargetOut)
+{
+  nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(aDoc);
+  nsCOMPtr<EventTarget> target(do_QueryInterface(aTarget));
+  NS_ENSURE_TRUE(domDoc && target, NS_ERROR_INVALID_ARG);
+
+  nsCOMPtr<nsIDOMEvent> event;
+  nsresult rv =
+    domDoc->CreateEvent(NS_LITERAL_STRING("Events"), getter_AddRefs(event));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  event->InitEvent(aEventName, aCanBubble, aCancelable);
+  event->SetTrusted(aTrusted);
+
+  rv = event->SetTarget(target);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  event.forget(aEvent);
+  target.forget(aTargetOut);
+  return NS_OK;
+}
+
+// static
+nsresult
+nsContentUtils::DispatchTrustedEvent(nsIDocument* aDoc, nsISupports* aTarget,
+                                     const nsAString& aEventName,
+                                     bool aCanBubble, bool aCancelable,
+                                     bool *aDefaultAction)
+{
+  return DispatchEvent(aDoc, aTarget, aEventName, aCanBubble, aCancelable,
+                       true, aDefaultAction);
+}
+
+// static
+nsresult
+nsContentUtils::DispatchUntrustedEvent(nsIDocument* aDoc, nsISupports* aTarget,
+                                       const nsAString& aEventName,
+                                       bool aCanBubble, bool aCancelable,
+                                       bool *aDefaultAction)
+{
+  return DispatchEvent(aDoc, aTarget, aEventName, aCanBubble, aCancelable,
+                       false, aDefaultAction);
+}
+
+// static
+nsresult
+nsContentUtils::DispatchEvent(nsIDocument* aDoc, nsISupports* aTarget,
+                              const nsAString& aEventName,
+                              bool aCanBubble, bool aCancelable,
+                              bool aTrusted, bool *aDefaultAction,
+                              bool aOnlyChromeDispatch)
+{
+  nsCOMPtr<nsIDOMEvent> event;
+  nsCOMPtr<EventTarget> target;
+  nsresult rv = GetEventAndTarget(aDoc, aTarget, aEventName, aCanBubble,
+                                  aCancelable, aTrusted, getter_AddRefs(event),
+                                  getter_AddRefs(target));
+  NS_ENSURE_SUCCESS(rv, rv);
+  event->WidgetEventPtr()->mFlags.mOnlyChromeDispatch = aOnlyChromeDispatch;
+
+  bool dummy;
+  return target->DispatchEvent(event, aDefaultAction ? aDefaultAction : &dummy);
+}
+
+nsresult
+nsContentUtils::DispatchChromeEvent(nsIDocument *aDoc,
+                                    nsISupports *aTarget,
+                                    const nsAString& aEventName,
+                                    bool aCanBubble, bool aCancelable,
+                                    bool *aDefaultAction)
+{
+
+  nsCOMPtr<nsIDOMEvent> event;
+  nsCOMPtr<EventTarget> target;
+  nsresult rv = GetEventAndTarget(aDoc, aTarget, aEventName, aCanBubble,
+                                  aCancelable, true, getter_AddRefs(event),
+                                  getter_AddRefs(target));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  NS_ASSERTION(aDoc, "GetEventAndTarget lied?");
+  if (!aDoc->GetWindow())
+    return NS_ERROR_INVALID_ARG;
+
+  EventTarget* piTarget = aDoc->GetWindow()->GetParentTarget();
+  if (!piTarget)
+    return NS_ERROR_INVALID_ARG;
+
+  nsEventStatus status = nsEventStatus_eIgnore;
+  rv = piTarget->DispatchDOMEvent(nullptr, event, nullptr, &status);
+  if (aDefaultAction) {
+    *aDefaultAction = (status != nsEventStatus_eConsumeNoDefault);
+  }
+  return rv;
+}
+
+/* static */
+nsresult
+nsContentUtils::DispatchFocusChromeEvent(nsPIDOMWindowOuter* aWindow)
+{
+  MOZ_ASSERT(aWindow);
+
+  nsCOMPtr<nsIDocument> doc = aWindow->GetExtantDoc();
+  if (!doc) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return DispatchChromeEvent(doc, aWindow,
+                             NS_LITERAL_STRING("DOMServiceWorkerFocusClient"),
+                             true, true);
+}
+
+nsresult
+nsContentUtils::DispatchEventOnlyToChrome(nsIDocument* aDoc,
+                                          nsISupports* aTarget,
+                                          const nsAString& aEventName,
+                                          bool aCanBubble, bool aCancelable,
+                                          bool* aDefaultAction)
+{
+  return DispatchEvent(aDoc, aTarget, aEventName, aCanBubble, aCancelable,
+                       true, aDefaultAction, true);
+}
+
+/* static */
+Element*
+nsContentUtils::MatchElementId(nsIContent *aContent, const nsIAtom* aId)
+{
+  for (nsIContent* cur = aContent;
+       cur;
+       cur = cur->GetNextNode(aContent)) {
+    if (aId == cur->GetID()) {
+      return cur->AsElement();
+    }
+  }
+
+  return nullptr;
+}
+
+/* static */
+Element *
+nsContentUtils::MatchElementId(nsIContent *aContent, const nsAString& aId)
+{
+  NS_PRECONDITION(!aId.IsEmpty(), "Will match random elements");
+
+  // ID attrs are generally stored as atoms, so just atomize this up front
+  nsCOMPtr<nsIAtom> id(NS_Atomize(aId));
+  if (!id) {
+    // OOM, so just bail
+    return nullptr;
+  }
+
+  return MatchElementId(aContent, id);
+}
+
+/* static */
+nsIDocument*
+nsContentUtils::GetSubdocumentWithOuterWindowId(nsIDocument *aDocument,
+                                                uint64_t aOuterWindowId)
+{
+  if (!aDocument || !aOuterWindowId) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsPIDOMWindowOuter> window = nsGlobalWindow::GetOuterWindowWithId(aOuterWindowId)->AsOuter();
+  if (!window) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsIDocument> foundDoc = window->GetDoc();
+  if (nsContentUtils::ContentIsCrossDocDescendantOf(foundDoc, aDocument)) {
+    // Note that ContentIsCrossDocDescendantOf will return true if
+    // foundDoc == aDocument.
+    return foundDoc;
+  }
+
+  return nullptr;
+}
+
+// Convert the string from the given encoding to Unicode.
+/* static */
+nsresult
+nsContentUtils::ConvertStringFromEncoding(const nsACString& aEncoding,
+                                          const nsACString& aInput,
+                                          nsAString& aOutput)
+{
+  nsAutoCString encoding;
+  if (aEncoding.IsEmpty()) {
+    encoding.AssignLiteral("UTF-8");
+  } else {
+    encoding.Assign(aEncoding);
+  }
+
+  ErrorResult rv;
+  nsAutoPtr<TextDecoder> decoder(new TextDecoder());
+  decoder->InitWithEncoding(encoding, false);
+
+  decoder->Decode(aInput.BeginReading(), aInput.Length(), false,
+                  aOutput, rv);
+  return rv.StealNSResult();
+}
+
+/* static */
+bool
+nsContentUtils::CheckForBOM(const unsigned char* aBuffer, uint32_t aLength,
+                            nsACString& aCharset)
+{
+  bool found = true;
+  aCharset.Truncate();
+  if (aLength >= 3 &&
+      aBuffer[0] == 0xEF &&
+      aBuffer[1] == 0xBB &&
+      aBuffer[2] == 0xBF) {
+    aCharset = "UTF-8";
+  }
+  else if (aLength >= 2 &&
+           aBuffer[0] == 0xFE && aBuffer[1] == 0xFF) {
+    aCharset = "UTF-16BE";
+  }
+  else if (aLength >= 2 &&
+           aBuffer[0] == 0xFF && aBuffer[1] == 0xFE) {
+    aCharset = "UTF-16LE";
+  } else {
+    found = false;
+  }
+
+  return found;
+}
+
+/* static */
+void
+nsContentUtils::RegisterShutdownObserver(nsIObserver* aObserver)
+{
+  nsCOMPtr<nsIObserverService> observerService =
+    mozilla::services::GetObserverService();
+  if (observerService) {
+    observerService->AddObserver(aObserver,
+                                 NS_XPCOM_SHUTDOWN_OBSERVER_ID,
+                                 false);
+  }
+}
+
+/* static */
+void
+nsContentUtils::UnregisterShutdownObserver(nsIObserver* aObserver)
+{
+  nsCOMPtr<nsIObserverService> observerService =
+    mozilla::services::GetObserverService();
+  if (observerService) {
+    observerService->RemoveObserver(aObserver, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
+  }
+}
+
+/* static */
+bool
+nsContentUtils::HasNonEmptyAttr(const nsIContent* aContent, int32_t aNameSpaceID,
+                                nsIAtom* aName)
+{
+  static nsIContent::AttrValuesArray strings[] = {&nsGkAtoms::_empty, nullptr};
+  return aContent->FindAttrValueIn(aNameSpaceID, aName, strings, eCaseMatters)
+    == nsIContent::ATTR_VALUE_NO_MATCH;
+}
+
+/* static */
+bool
+nsContentUtils::HasMutationListeners(nsINode* aNode,
+                                     uint32_t aType,
+                                     nsINode* aTargetForSubtreeModified)
+{
+  nsIDocument* doc = aNode->OwnerDoc();
+
+  // global object will be null for documents that don't have windows.
+  nsPIDOMWindowInner* window = doc->GetInnerWindow();
+  // This relies on EventListenerManager::AddEventListener, which sets
+  // all mutation bits when there is a listener for DOMSubtreeModified event.
+  if (window && !window->HasMutationListeners(aType)) {
+    return false;
+  }
+
+  if (aNode->IsNodeOfType(nsINode::eCONTENT) &&
+      static_cast<nsIContent*>(aNode)->ChromeOnlyAccess()) {
+    return false;
+  }
+
+  doc->MayDispatchMutationEvent(aTargetForSubtreeModified);
+
+  // If we have a window, we can check it for mutation listeners now.
+  if (aNode->IsInUncomposedDoc()) {
+    nsCOMPtr<EventTarget> piTarget(do_QueryInterface(window));
+    if (piTarget) {
+      EventListenerManager* manager = piTarget->GetExistingListenerManager();
+      if (manager && manager->HasMutationListeners()) {
+        return true;
+      }
+    }
+  }
+
+  // If we have a window, we know a mutation listener is registered, but it
+  // might not be in our chain.  If we don't have a window, we might have a
+  // mutation listener.  Check quickly to see.
+  while (aNode) {
+    EventListenerManager* manager = aNode->GetExistingListenerManager();
+    if (manager && manager->HasMutationListeners()) {
+      return true;
+    }
+
+    if (aNode->IsNodeOfType(nsINode::eCONTENT)) {
+      nsIContent* content = static_cast<nsIContent*>(aNode);
+      nsIContent* insertionParent = content->GetXBLInsertionParent();
+      if (insertionParent) {
+        aNode = insertionParent;
+        continue;
+      }
+    }
+    aNode = aNode->GetParentNode();
+  }
+
+  return false;
+}
+
+/* static */
+bool
+nsContentUtils::HasMutationListeners(nsIDocument* aDocument,
+                                     uint32_t aType)
+{
+  nsPIDOMWindowInner* window = aDocument ?
+    aDocument->GetInnerWindow() : nullptr;
+
+  // This relies on EventListenerManager::AddEventListener, which sets
+  // all mutation bits when there is a listener for DOMSubtreeModified event.
+  return !window || window->HasMutationListeners(aType);
+}
+
+void
+nsContentUtils::MaybeFireNodeRemoved(nsINode* aChild, nsINode* aParent,
+                                     nsIDocument* aOwnerDoc)
+{
+  NS_PRECONDITION(aChild, "Missing child");
+  NS_PRECONDITION(aChild->GetParentNode() == aParent, "Wrong parent");
+  NS_PRECONDITION(aChild->OwnerDoc() == aOwnerDoc, "Wrong owner-doc");
+
+  // Having an explicit check here since it's an easy mistake to fall into,
+  // and there might be existing code with problems. We'd rather be safe
+  // than fire DOMNodeRemoved in all corner cases. We also rely on it for
+  // nsAutoScriptBlockerSuppressNodeRemoved.
+  if (!IsSafeToRunScript()) {
+    // This checks that IsSafeToRunScript is true since we don't want to fire
+    // events when that is false. We can't rely on EventDispatcher to assert
+    // this in this situation since most of the time there are no mutation
+    // event listeners, in which case we won't even attempt to dispatch events.
+    // However this also allows for two exceptions. First off, we don't assert
+    // if the mutation happens to native anonymous content since we never fire
+    // mutation events on such content anyway.
+    // Second, we don't assert if sDOMNodeRemovedSuppressCount is true since
+    // that is a know case when we'd normally fire a mutation event, but can't
+    // make that safe and so we suppress it at this time. Ideally this should
+    // go away eventually.
+    if (!(aChild->IsContent() && aChild->AsContent()->IsInNativeAnonymousSubtree()) &&
+        !sDOMNodeRemovedSuppressCount) {
+      NS_ERROR("Want to fire DOMNodeRemoved event, but it's not safe");
+      WarnScriptWasIgnored(aOwnerDoc);
+    }
+    return;
+  }
+
+  if (HasMutationListeners(aChild,
+        NS_EVENT_BITS_MUTATION_NODEREMOVED, aParent)) {
+    InternalMutationEvent mutation(true, eLegacyNodeRemoved);
+    mutation.mRelatedNode = do_QueryInterface(aParent);
+
+    mozAutoSubtreeModified subtree(aOwnerDoc, aParent);
+    EventDispatcher::Dispatch(aChild, nullptr, &mutation);
+  }
+}
+
+void
+nsContentUtils::UnmarkGrayJSListenersInCCGenerationDocuments()
+{
+  if (!sEventListenerManagersHash) {
+    return;
+  }
+
+  for (auto i = sEventListenerManagersHash->Iter(); !i.Done(); i.Next()) {
+    auto entry = static_cast<EventListenerManagerMapEntry*>(i.Get());
+    nsINode* n = static_cast<nsINode*>(entry->mListenerManager->GetTarget());
+    if (n && n->IsInUncomposedDoc() &&
+        nsCCUncollectableMarker::InGeneration(n->OwnerDoc()->GetMarkedCCGeneration())) {
+      entry->mListenerManager->MarkForCC();
+    }
+  }
+}
+
+/* static */
+void
+nsContentUtils::TraverseListenerManager(nsINode *aNode,
+                                        nsCycleCollectionTraversalCallback &cb)
+{
+  if (!sEventListenerManagersHash) {
+    // We're already shut down, just return.
+    return;
+  }
+
+  auto entry = static_cast<EventListenerManagerMapEntry*>
+                          (sEventListenerManagersHash->Search(aNode));
+  if (entry) {
+    CycleCollectionNoteChild(cb, entry->mListenerManager.get(),
+                             "[via hash] mListenerManager");
+  }
+}
+
+EventListenerManager*
+nsContentUtils::GetListenerManagerForNode(nsINode *aNode)
+{
+  if (!sEventListenerManagersHash) {
+    // We're already shut down, don't bother creating an event listener
+    // manager.
+
+    return nullptr;
+  }
+
+  auto entry =
+    static_cast<EventListenerManagerMapEntry*>
+               (sEventListenerManagersHash->Add(aNode, fallible));
+
+  if (!entry) {
+    return nullptr;
+  }
+
+  if (!entry->mListenerManager) {
+    entry->mListenerManager = new EventListenerManager(aNode);
+
+    aNode->SetFlags(NODE_HAS_LISTENERMANAGER);
+  }
+
+  return entry->mListenerManager;
+}
+
+EventListenerManager*
+nsContentUtils::GetExistingListenerManagerForNode(const nsINode *aNode)
+{
+  if (!aNode->HasFlag(NODE_HAS_LISTENERMANAGER)) {
+    return nullptr;
+  }
+
+  if (!sEventListenerManagersHash) {
+    // We're already shut down, don't bother creating an event listener
+    // manager.
+
+    return nullptr;
+  }
+
+  auto entry = static_cast<EventListenerManagerMapEntry*>
+                          (sEventListenerManagersHash->Search(aNode));
+  if (entry) {
+    return entry->mListenerManager;
+  }
+
+  return nullptr;
+}
+
+/* static */
+void
+nsContentUtils::RemoveListenerManager(nsINode *aNode)
+{
+  if (sEventListenerManagersHash) {
+    auto entry = static_cast<EventListenerManagerMapEntry*>
+                            (sEventListenerManagersHash->Search(aNode));
+    if (entry) {
+      RefPtr<EventListenerManager> listenerManager;
+      listenerManager.swap(entry->mListenerManager);
+      // Remove the entry and *then* do operations that could cause further
+      // modification of sEventListenerManagersHash.  See bug 334177.
+      sEventListenerManagersHash->RawRemove(entry);
+      if (listenerManager) {
+        listenerManager->Disconnect();
+      }
+    }
+  }
+}
+
+/* static */
+bool
+nsContentUtils::IsValidNodeName(nsIAtom *aLocalName, nsIAtom *aPrefix,
+                                int32_t aNamespaceID)
+{
+  if (aNamespaceID == kNameSpaceID_Unknown) {
+    return false;
+  }
+
+  if (!aPrefix) {
+    // If the prefix is null, then either the QName must be xmlns or the
+    // namespace must not be XMLNS.
+    return (aLocalName == nsGkAtoms::xmlns) ==
+           (aNamespaceID == kNameSpaceID_XMLNS);
+  }
+
+  // If the prefix is non-null then the namespace must not be null.
+  if (aNamespaceID == kNameSpaceID_None) {
+    return false;
+  }
+
+  // If the namespace is the XMLNS namespace then the prefix must be xmlns,
+  // but the localname must not be xmlns.
+  if (aNamespaceID == kNameSpaceID_XMLNS) {
+    return aPrefix == nsGkAtoms::xmlns && aLocalName != nsGkAtoms::xmlns;
+  }
+
+  // If the namespace is not the XMLNS namespace then the prefix must not be
+  // xmlns.
+  // If the namespace is the XML namespace then the prefix can be anything.
+  // If the namespace is not the XML namespace then the prefix must not be xml.
+  return aPrefix != nsGkAtoms::xmlns &&
+         (aNamespaceID == kNameSpaceID_XML || aPrefix != nsGkAtoms::xml);
+}
+
+/* static */
+nsresult
+nsContentUtils::CreateContextualFragment(nsINode* aContextNode,
+                                         const nsAString& aFragment,
+                                         bool aPreventScriptExecution,
+                                         nsIDOMDocumentFragment** aReturn)
+{
+  ErrorResult rv;
+  *aReturn = CreateContextualFragment(aContextNode, aFragment,
+                                      aPreventScriptExecution, rv).take();
+  return rv.StealNSResult();
+}
+
+already_AddRefed<DocumentFragment>
+nsContentUtils::CreateContextualFragment(nsINode* aContextNode,
+                                         const nsAString& aFragment,
+                                         bool aPreventScriptExecution,
+                                         ErrorResult& aRv)
+{
+  if (!aContextNode) {
+    aRv.Throw(NS_ERROR_INVALID_ARG);
+    return nullptr;
+  }
+
+  // If we don't have a document here, we can't get the right security context
+  // for compiling event handlers... so just bail out.
+  nsCOMPtr<nsIDocument> document = aContextNode->OwnerDoc();
+  bool isHTML = document->IsHTMLDocument();
+#ifdef DEBUG
+  nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(document);
+  NS_ASSERTION(!isHTML || htmlDoc, "Should have HTMLDocument here!");
+#endif
+
+  if (isHTML) {
+    RefPtr<DocumentFragment> frag =
+      new DocumentFragment(document->NodeInfoManager());
+
+    nsCOMPtr<nsIContent> contextAsContent = do_QueryInterface(aContextNode);
+    if (contextAsContent && !contextAsContent->IsElement()) {
+      contextAsContent = contextAsContent->GetParent();
+      if (contextAsContent && !contextAsContent->IsElement()) {
+        // can this even happen?
+        contextAsContent = nullptr;
+      }
+    }
+
+    if (contextAsContent && !contextAsContent->IsHTMLElement(nsGkAtoms::html)) {
+      aRv = ParseFragmentHTML(aFragment, frag,
+                              contextAsContent->NodeInfo()->NameAtom(),
+                              contextAsContent->GetNameSpaceID(),
+                              (document->GetCompatibilityMode() ==
+                               eCompatibility_NavQuirks),
+                              aPreventScriptExecution);
+    } else {
+      aRv = ParseFragmentHTML(aFragment, frag,
+                              nsGkAtoms::body,
+                              kNameSpaceID_XHTML,
+                              (document->GetCompatibilityMode() ==
+                               eCompatibility_NavQuirks),
+                              aPreventScriptExecution);
+    }
+
+    return frag.forget();
+  }
+
+  AutoTArray<nsString, 32> tagStack;
+  nsAutoString uriStr, nameStr;
+  nsCOMPtr<nsIContent> content = do_QueryInterface(aContextNode);
+  // just in case we have a text node
+  if (content && !content->IsElement())
+    content = content->GetParent();
+
+  while (content && content->IsElement()) {
+    nsString& tagName = *tagStack.AppendElement();
+    tagName = content->NodeInfo()->QualifiedName();
+
+    // see if we need to add xmlns declarations
+    uint32_t count = content->GetAttrCount();
+    bool setDefaultNamespace = false;
+    if (count > 0) {
+      uint32_t index;
+
+      for (index = 0; index < count; index++) {
+        const BorrowedAttrInfo info = content->GetAttrInfoAt(index);
+        const nsAttrName* name = info.mName;
+        if (name->NamespaceEquals(kNameSpaceID_XMLNS)) {
+          info.mValue->ToString(uriStr);
+
+          // really want something like nsXMLContentSerializer::SerializeAttr
+          tagName.AppendLiteral(" xmlns"); // space important
+          if (name->GetPrefix()) {
+            tagName.Append(char16_t(':'));
+            name->LocalName()->ToString(nameStr);
+            tagName.Append(nameStr);
+          } else {
+            setDefaultNamespace = true;
+          }
+          tagName.AppendLiteral("=\"");
+          tagName.Append(uriStr);
+          tagName.Append('"');
+        }
+      }
+    }
+
+    if (!setDefaultNamespace) {
+      mozilla::dom::NodeInfo* info = content->NodeInfo();
+      if (!info->GetPrefixAtom() &&
+          info->NamespaceID() != kNameSpaceID_None) {
+        // We have no namespace prefix, but have a namespace ID.  Push
+        // default namespace attr in, so that our kids will be in our
+        // namespace.
+        info->GetNamespaceURI(uriStr);
+        tagName.AppendLiteral(" xmlns=\"");
+        tagName.Append(uriStr);
+        tagName.Append('"');
+      }
+    }
+
+    content = content->GetParent();
+  }
+
+  nsCOMPtr<nsIDOMDocumentFragment> frag;
+  aRv = ParseFragmentXML(aFragment, document, tagStack,
+                         aPreventScriptExecution, getter_AddRefs(frag));
+  return frag.forget().downcast<DocumentFragment>();
+}
+
+/* static */
+void
+nsContentUtils::DropFragmentParsers()
+{
+  NS_IF_RELEASE(sHTMLFragmentParser);
+  NS_IF_RELEASE(sXMLFragmentParser);
+  NS_IF_RELEASE(sXMLFragmentSink);
+}
+
+/* static */
+void
+nsContentUtils::XPCOMShutdown()
+{
+  nsContentUtils::DropFragmentParsers();
+}
+
+/* static */
+nsresult
+nsContentUtils::ParseFragmentHTML(const nsAString& aSourceBuffer,
+                                  nsIContent* aTargetNode,
+                                  nsIAtom* aContextLocalName,
+                                  int32_t aContextNamespace,
+                                  bool aQuirks,
+                                  bool aPreventScriptExecution)
+{
+  AutoTimelineMarker m(aTargetNode->OwnerDoc()->GetDocShell(), "Parse HTML");
+
+  if (nsContentUtils::sFragmentParsingActive) {
+    NS_NOTREACHED("Re-entrant fragment parsing attempted.");
+    return NS_ERROR_DOM_INVALID_STATE_ERR;
+  }
+  mozilla::AutoRestore<bool> guard(nsContentUtils::sFragmentParsingActive);
+  nsContentUtils::sFragmentParsingActive = true;
+  if (!sHTMLFragmentParser) {
+    NS_ADDREF(sHTMLFragmentParser = new nsHtml5StringParser());
+    // Now sHTMLFragmentParser owns the object
+  }
+  nsresult rv =
+    sHTMLFragmentParser->ParseFragment(aSourceBuffer,
+                                       aTargetNode,
+                                       aContextLocalName,
+                                       aContextNamespace,
+                                       aQuirks,
+                                       aPreventScriptExecution);
+  return rv;
+}
+
+/* static */
+nsresult
+nsContentUtils::ParseDocumentHTML(const nsAString& aSourceBuffer,
+                                  nsIDocument* aTargetDocument,
+                                  bool aScriptingEnabledForNoscriptParsing)
+{
+  AutoTimelineMarker m(aTargetDocument->GetDocShell(), "Parse HTML");
+
+  if (nsContentUtils::sFragmentParsingActive) {
+    NS_NOTREACHED("Re-entrant fragment parsing attempted.");
+    return NS_ERROR_DOM_INVALID_STATE_ERR;
+  }
+  mozilla::AutoRestore<bool> guard(nsContentUtils::sFragmentParsingActive);
+  nsContentUtils::sFragmentParsingActive = true;
+  if (!sHTMLFragmentParser) {
+    NS_ADDREF(sHTMLFragmentParser = new nsHtml5StringParser());
+    // Now sHTMLFragmentParser owns the object
+  }
+  nsresult rv =
+    sHTMLFragmentParser->ParseDocument(aSourceBuffer,
+                                       aTargetDocument,
+                                       aScriptingEnabledForNoscriptParsing);
+  return rv;
+}
+
+/* static */
+nsresult
+nsContentUtils::ParseFragmentXML(const nsAString& aSourceBuffer,
+                                 nsIDocument* aDocument,
+                                 nsTArray<nsString>& aTagStack,
+                                 bool aPreventScriptExecution,
+                                 nsIDOMDocumentFragment** aReturn)
+{
+  AutoTimelineMarker m(aDocument->GetDocShell(), "Parse XML");
+
+  if (nsContentUtils::sFragmentParsingActive) {
+    NS_NOTREACHED("Re-entrant fragment parsing attempted.");
+    return NS_ERROR_DOM_INVALID_STATE_ERR;
+  }
+  mozilla::AutoRestore<bool> guard(nsContentUtils::sFragmentParsingActive);
+  nsContentUtils::sFragmentParsingActive = true;
+  if (!sXMLFragmentParser) {
+    nsCOMPtr<nsIParser> parser = do_CreateInstance(kCParserCID);
+    parser.forget(&sXMLFragmentParser);
+    // sXMLFragmentParser now owns the parser
+  }
+  if (!sXMLFragmentSink) {
+    NS_NewXMLFragmentContentSink(&sXMLFragmentSink);
+    // sXMLFragmentSink now owns the sink
+  }
+  nsCOMPtr<nsIContentSink> contentsink = do_QueryInterface(sXMLFragmentSink);
+  MOZ_ASSERT(contentsink, "Sink doesn't QI to nsIContentSink!");
+  sXMLFragmentParser->SetContentSink(contentsink);
+
+  sXMLFragmentSink->SetTargetDocument(aDocument);
+  sXMLFragmentSink->SetPreventScriptExecution(aPreventScriptExecution);
+
+  nsresult rv =
+    sXMLFragmentParser->ParseFragment(aSourceBuffer,
+                                      aTagStack);
+  if (NS_FAILED(rv)) {
+    // Drop the fragment parser and sink that might be in an inconsistent state
+    NS_IF_RELEASE(sXMLFragmentParser);
+    NS_IF_RELEASE(sXMLFragmentSink);
+    return rv;
+  }
+
+  rv = sXMLFragmentSink->FinishFragmentParsing(aReturn);
+
+  sXMLFragmentParser->Reset();
+
+  return rv;
+}
+
+/* static */
+nsresult
+nsContentUtils::ConvertToPlainText(const nsAString& aSourceBuffer,
+                                   nsAString& aResultBuffer,
+                                   uint32_t aFlags,
+                                   uint32_t aWrapCol)
+{
+  nsCOMPtr<nsIURI> uri;
+  NS_NewURI(getter_AddRefs(uri), "about:blank");
+  nsCOMPtr<nsIPrincipal> principal = nsNullPrincipal::Create();
+  nsCOMPtr<nsIDOMDocument> domDocument;
+  nsresult rv = NS_NewDOMDocument(getter_AddRefs(domDocument),
+                                  EmptyString(),
+                                  EmptyString(),
+                                  nullptr,
+                                  uri,
+                                  uri,
+                                  principal,
+                                  true,
+                                  nullptr,
+                                  DocumentFlavorHTML);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIDocument> document = do_QueryInterface(domDocument);
+  rv = nsContentUtils::ParseDocumentHTML(aSourceBuffer, document,
+    !(aFlags & nsIDocumentEncoder::OutputNoScriptContent));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIDocumentEncoder> encoder = do_CreateInstance(
+    "@mozilla.org/layout/documentEncoder;1?type=text/plain");
+
+  rv = encoder->Init(domDocument, NS_LITERAL_STRING("text/plain"), aFlags);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  encoder->SetWrapColumn(aWrapCol);
+
+  return encoder->EncodeToString(aResultBuffer);
+}
+
+/* static */
+nsresult
+nsContentUtils::SetNodeTextContent(nsIContent* aContent,
+                                   const nsAString& aValue,
+                                   bool aTryReuse)
+{
+  // Fire DOMNodeRemoved mutation events before we do anything else.
+  nsCOMPtr<nsIContent> owningContent;
+
+  // Batch possible DOMSubtreeModified events.
+  mozAutoSubtreeModified subtree(nullptr, nullptr);
+
+  // Scope firing mutation events so that we don't carry any state that
+  // might be stale
+  {
+    // We're relying on mozAutoSubtreeModified to keep a strong reference if
+    // needed.
+    nsIDocument* doc = aContent->OwnerDoc();
+
+    // Optimize the common case of there being no observers
+    if (HasMutationListeners(doc, NS_EVENT_BITS_MUTATION_NODEREMOVED)) {
+      subtree.UpdateTarget(doc, nullptr);
+      owningContent = aContent;
+      nsCOMPtr<nsINode> child;
+      bool skipFirst = aTryReuse;
+      for (child = aContent->GetFirstChild();
+           child && child->GetParentNode() == aContent;
+           child = child->GetNextSibling()) {
+        if (skipFirst && child->IsNodeOfType(nsINode::eTEXT)) {
+          skipFirst = false;
+          continue;
+        }
+        nsContentUtils::MaybeFireNodeRemoved(child, aContent, doc);
+      }
+    }
+  }
+
+  // Might as well stick a batch around this since we're performing several
+  // mutations.
+  mozAutoDocUpdate updateBatch(aContent->GetComposedDoc(),
+    UPDATE_CONTENT_MODEL, true);
+  nsAutoMutationBatch mb;
+
+  uint32_t childCount = aContent->GetChildCount();
+
+  if (aTryReuse && !aValue.IsEmpty()) {
+    uint32_t removeIndex = 0;
+
+    for (uint32_t i = 0; i < childCount; ++i) {
+      nsIContent* child = aContent->GetChildAt(removeIndex);
+      if (removeIndex == 0 && child && child->IsNodeOfType(nsINode::eTEXT)) {
+        nsresult rv = child->SetText(aValue, true);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        removeIndex = 1;
+      }
+      else {
+        aContent->RemoveChildAt(removeIndex, true);
+      }
+    }
+
+    if (removeIndex == 1) {
+      return NS_OK;
+    }
+  }
+  else {
+    mb.Init(aContent, true, false);
+    for (uint32_t i = 0; i < childCount; ++i) {
+      aContent->RemoveChildAt(0, true);
+    }
+  }
+  mb.RemovalDone();
+
+  if (aValue.IsEmpty()) {
+    return NS_OK;
+  }
+
+  RefPtr<nsTextNode> textContent =
+    new nsTextNode(aContent->NodeInfo()->NodeInfoManager());
+
+  textContent->SetText(aValue, true);
+
+  nsresult rv = aContent->AppendChildTo(textContent, true);
+  mb.NodesAdded();
+  return rv;
+}
+
+static bool
+AppendNodeTextContentsRecurse(nsINode* aNode, nsAString& aResult,
+                              const fallible_t& aFallible)
+{
+  for (nsIContent* child = aNode->GetFirstChild();
+       child;
+       child = child->GetNextSibling()) {
+    if (child->IsElement()) {
+      bool ok = AppendNodeTextContentsRecurse(child, aResult,
+                                              aFallible);
+      if (!ok) {
+        return false;
+      }
+    }
+    else if (child->IsNodeOfType(nsINode::eTEXT)) {
+      bool ok = child->AppendTextTo(aResult, aFallible);
+      if (!ok) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+/* static */
+bool
+nsContentUtils::AppendNodeTextContent(nsINode* aNode, bool aDeep,
+                                      nsAString& aResult,
+                                      const fallible_t& aFallible)
+{
+  if (aNode->IsNodeOfType(nsINode::eTEXT)) {
+    return static_cast<nsIContent*>(aNode)->AppendTextTo(aResult,
+                                                         aFallible);
+  }
+  else if (aDeep) {
+    return AppendNodeTextContentsRecurse(aNode, aResult, aFallible);
+  }
+  else {
+    for (nsIContent* child = aNode->GetFirstChild();
+         child;
+         child = child->GetNextSibling()) {
+      if (child->IsNodeOfType(nsINode::eTEXT)) {
+        bool ok = child->AppendTextTo(aResult, fallible);
+        if (!ok) {
+            return false;
+        }
+      }
+    }
+  }
+
+  return true;
+}
+
+bool
+nsContentUtils::HasNonEmptyTextContent(nsINode* aNode,
+                                       TextContentDiscoverMode aDiscoverMode)
+{
+  for (nsIContent* child = aNode->GetFirstChild();
+       child;
+       child = child->GetNextSibling()) {
+    if (child->IsNodeOfType(nsINode::eTEXT) &&
+        child->TextLength() > 0) {
+        return true;
+    }
+
+    if (aDiscoverMode == eRecurseIntoChildren &&
+        HasNonEmptyTextContent(child, aDiscoverMode)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/* static */
+bool
+nsContentUtils::IsInSameAnonymousTree(const nsINode* aNode,
+                                      const nsIContent* aContent)
+{
+  NS_PRECONDITION(aNode,
+                  "Must have a node to work with");
+  NS_PRECONDITION(aContent,
+                  "Must have a content to work with");
+
+  if (!aNode->IsNodeOfType(nsINode::eCONTENT)) {
+    /**
+     * The root isn't an nsIContent, so it's a document or attribute.  The only
+     * nodes in the same anonymous subtree as it will have a null
+     * bindingParent.
+     *
+     * XXXbz strictly speaking, that's not true for attribute nodes.
+     */
+    return aContent->GetBindingParent() == nullptr;
+  }
+
+  const nsIContent* nodeAsContent = static_cast<const nsIContent*>(aNode);
+
+  // For nodes in a shadow tree, it is insufficient to simply compare
+  // the binding parent because a node may host multiple ShadowRoots,
+  // thus nodes in different shadow tree may have the same binding parent.
+  if (aNode->IsInShadowTree()) {
+    return nodeAsContent->GetContainingShadow() ==
+      aContent->GetContainingShadow();
+  }
+
+  return nodeAsContent->GetBindingParent() == aContent->GetBindingParent();
+}
+
+class AnonymousContentDestroyer : public Runnable {
+public:
+  explicit AnonymousContentDestroyer(nsCOMPtr<nsIContent>* aContent) {
+    mContent.swap(*aContent);
+    mParent = mContent->GetParent();
+    mDoc = mContent->OwnerDoc();
+  }
+  explicit AnonymousContentDestroyer(nsCOMPtr<Element>* aElement) {
+    mContent = aElement->forget();
+    mParent = mContent->GetParent();
+    mDoc = mContent->OwnerDoc();
+  }
+  NS_IMETHOD Run() override {
+    mContent->UnbindFromTree();
+    return NS_OK;
+  }
+private:
+  nsCOMPtr<nsIContent> mContent;
+  // Hold strong refs to the parent content and document so that they
+  // don't die unexpectedly
+  nsCOMPtr<nsIDocument> mDoc;
+  nsCOMPtr<nsIContent> mParent;
+};
+
+/* static */
+void
+nsContentUtils::DestroyAnonymousContent(nsCOMPtr<nsIContent>* aContent)
+{
+  if (*aContent) {
+    AddScriptRunner(new AnonymousContentDestroyer(aContent));
+  }
+}
+
+/* static */
+void
+nsContentUtils::DestroyAnonymousContent(nsCOMPtr<Element>* aElement)
+{
+  if (*aElement) {
+    AddScriptRunner(new AnonymousContentDestroyer(aElement));
+  }
+}
+
+/* static */
+void
+nsContentUtils::NotifyInstalledMenuKeyboardListener(bool aInstalling)
+{
+  IMEStateManager::OnInstalledMenuKeyboardListener(aInstalling);
+}
+
+static bool SchemeIs(nsIURI* aURI, const char* aScheme)
+{
+  nsCOMPtr<nsIURI> baseURI = NS_GetInnermostURI(aURI);
+  NS_ENSURE_TRUE(baseURI, false);
+
+  bool isScheme = false;
+  return NS_SUCCEEDED(baseURI->SchemeIs(aScheme, &isScheme)) && isScheme;
+}
+
+bool
+nsContentUtils::IsSystemPrincipal(nsIPrincipal* aPrincipal)
+{
+  MOZ_ASSERT(IsInitialized());
+  return aPrincipal == sSystemPrincipal;
+}
+
+bool
+nsContentUtils::IsExpandedPrincipal(nsIPrincipal* aPrincipal)
+{
+  nsCOMPtr<nsIExpandedPrincipal> ep = do_QueryInterface(aPrincipal);
+  return !!ep;
+}
+
+nsIPrincipal*
+nsContentUtils::GetSystemPrincipal()
+{
+  MOZ_ASSERT(IsInitialized());
+  return sSystemPrincipal;
+}
+
+bool
+nsContentUtils::CombineResourcePrincipals(nsCOMPtr<nsIPrincipal>* aResourcePrincipal,
+                                          nsIPrincipal* aExtraPrincipal)
+{
+  if (!aExtraPrincipal) {
+    return false;
+  }
+  if (!*aResourcePrincipal) {
+    *aResourcePrincipal = aExtraPrincipal;
+    return true;
+  }
+  if (*aResourcePrincipal == aExtraPrincipal) {
+    return false;
+  }
+  bool subsumes;
+  if (NS_SUCCEEDED((*aResourcePrincipal)->Subsumes(aExtraPrincipal, &subsumes)) &&
+      subsumes) {
+    return false;
+  }
+  *aResourcePrincipal = sSystemPrincipal;
+  return true;
+}
+
+/* static */
+void
+nsContentUtils::TriggerLink(nsIContent *aContent, nsPresContext *aPresContext,
+                            nsIURI *aLinkURI, const nsString &aTargetSpec,
+                            bool aClick, bool aIsUserTriggered,
+                            bool aIsTrusted)
+{
+  NS_ASSERTION(aPresContext, "Need a nsPresContext");
+  NS_PRECONDITION(aLinkURI, "No link URI");
+
+  if (aContent->IsEditable()) {
+    return;
+  }
+
+  nsILinkHandler *handler = aPresContext->GetLinkHandler();
+  if (!handler) {
+    return;
+  }
+
+  if (!aClick) {
+    handler->OnOverLink(aContent, aLinkURI, aTargetSpec.get());
+    return;
+  }
+
+  // Check that this page is allowed to load this URI.
+  nsresult proceed = NS_OK;
+
+  if (sSecurityManager) {
+    uint32_t flag =
+      aIsUserTriggered ?
+      (uint32_t)nsIScriptSecurityManager::STANDARD :
+      (uint32_t)nsIScriptSecurityManager::LOAD_IS_AUTOMATIC_DOCUMENT_REPLACEMENT;
+    proceed =
+      sSecurityManager->CheckLoadURIWithPrincipal(aContent->NodePrincipal(),
+                                                  aLinkURI, flag);
+  }
+
+  // Only pass off the click event if the script security manager says it's ok.
+  // We need to rest aTargetSpec for forced downloads.
+  if (NS_SUCCEEDED(proceed)) {
+
+    // A link/area element with a download attribute is allowed to set
+    // a pseudo Content-Disposition header.
+    // For security reasons we only allow websites to declare same-origin resources
+    // as downloadable. If this check fails we will just do the normal thing
+    // (i.e. navigate to the resource).
+    nsAutoString fileName;
+    if ((!aContent->IsHTMLElement(nsGkAtoms::a) &&
+         !aContent->IsHTMLElement(nsGkAtoms::area) &&
+         !aContent->IsSVGElement(nsGkAtoms::a)) ||
+        !aContent->GetAttr(kNameSpaceID_None, nsGkAtoms::download, fileName) ||
+        NS_FAILED(aContent->NodePrincipal()->CheckMayLoad(aLinkURI, false, true))) {
+      fileName.SetIsVoid(true); // No actionable download attribute was found.
+    }
+
+    handler->OnLinkClick(aContent, aLinkURI,
+                         fileName.IsVoid() ? aTargetSpec.get() : EmptyString().get(),
+                         fileName, nullptr, nullptr, aIsTrusted);
+  }
+}
+
+/* static */
+void
+nsContentUtils::GetLinkLocation(Element* aElement, nsString& aLocationString)
+{
+  nsCOMPtr<nsIURI> hrefURI = aElement->GetHrefURI();
+  if (hrefURI) {
+    nsAutoCString specUTF8;
+    nsresult rv = hrefURI->GetSpec(specUTF8);
+    if (NS_SUCCEEDED(rv))
+      CopyUTF8toUTF16(specUTF8, aLocationString);
+  }
+}
+
+/* static */
+nsIWidget*
+nsContentUtils::GetTopLevelWidget(nsIWidget* aWidget)
+{
+  if (!aWidget)
+    return nullptr;
+
+  return aWidget->GetTopLevelWidget();
+}
+
+/* static */
+const nsDependentString
+nsContentUtils::GetLocalizedEllipsis()
+{
+  static char16_t sBuf[4] = { 0, 0, 0, 0 };
+  if (!sBuf[0]) {
+    nsAdoptingString tmp = Preferences::GetLocalizedString("intl.ellipsis");
+    uint32_t len = std::min(uint32_t(tmp.Length()),
+                          uint32_t(ArrayLength(sBuf) - 1));
+    CopyUnicodeTo(tmp, 0, sBuf, len);
+    if (!sBuf[0])
+      sBuf[0] = char16_t(0x2026);
+  }
+  return nsDependentString(sBuf);
+}
+
+/* static */
+void
+nsContentUtils::AddScriptBlocker()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!sScriptBlockerCount) {
+    MOZ_ASSERT(sRunnersCountAtFirstBlocker == 0,
+               "Should not already have a count");
+    sRunnersCountAtFirstBlocker = sBlockedScriptRunners ? sBlockedScriptRunners->Length() : 0;
+  }
+  ++sScriptBlockerCount;
+}
+
+#ifdef DEBUG
+static bool sRemovingScriptBlockers = false;
+#endif
+
+/* static */
+void
+nsContentUtils::RemoveScriptBlocker()
+{
+  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!sRemovingScriptBlockers);
+  NS_ASSERTION(sScriptBlockerCount != 0, "Negative script blockers");
+  --sScriptBlockerCount;
+  if (sScriptBlockerCount) {
+    return;
+  }
+
+  if (!sBlockedScriptRunners) {
+    return;
+  }
+
+  uint32_t firstBlocker = sRunnersCountAtFirstBlocker;
+  uint32_t lastBlocker = sBlockedScriptRunners->Length();
+  uint32_t originalFirstBlocker = firstBlocker;
+  uint32_t blockersCount = lastBlocker - firstBlocker;
+  sRunnersCountAtFirstBlocker = 0;
+  NS_ASSERTION(firstBlocker <= lastBlocker,
+               "bad sRunnersCountAtFirstBlocker");
+
+  while (firstBlocker < lastBlocker) {
+    nsCOMPtr<nsIRunnable> runnable;
+    runnable.swap((*sBlockedScriptRunners)[firstBlocker]);
+    ++firstBlocker;
+
+    // Calling the runnable can reenter us
+    runnable->Run();
+    // So can dropping the reference to the runnable
+    runnable = nullptr;
+
+    NS_ASSERTION(sRunnersCountAtFirstBlocker == 0,
+                 "Bad count");
+    NS_ASSERTION(!sScriptBlockerCount, "This is really bad");
+  }
+#ifdef DEBUG
+  AutoRestore<bool> removingScriptBlockers(sRemovingScriptBlockers);
+  sRemovingScriptBlockers = true;
+#endif
+  sBlockedScriptRunners->RemoveElementsAt(originalFirstBlocker, blockersCount);
+}
+
+/* static */
+nsIWindowProvider*
+nsContentUtils::GetWindowProviderForContentProcess()
+{
+  MOZ_ASSERT(XRE_IsContentProcess());
+  return ContentChild::GetSingleton();
+}
+
+/* static */
+already_AddRefed<nsPIDOMWindowOuter>
+nsContentUtils::GetMostRecentNonPBWindow()
+{
+  nsCOMPtr<nsIWindowMediator> windowMediator =
+    do_GetService(NS_WINDOWMEDIATOR_CONTRACTID);
+  nsCOMPtr<nsIWindowMediator_44> wm = do_QueryInterface(windowMediator);
+
+  nsCOMPtr<mozIDOMWindowProxy> window;
+  wm->GetMostRecentNonPBWindow(u"navigator:browser",
+                               getter_AddRefs(window));
+  nsCOMPtr<nsPIDOMWindowOuter> pwindow;
+  pwindow = do_QueryInterface(window);
+
+  return pwindow.forget();
+}
+
+/* static */
+void
+nsContentUtils::WarnScriptWasIgnored(nsIDocument* aDocument)
+{
+  nsAutoString msg;
+  if (aDocument) {
+    nsCOMPtr<nsIURI> uri = aDocument->GetDocumentURI();
+    if (uri) {
+      msg.Append(NS_ConvertUTF8toUTF16(uri->GetSpecOrDefault()));
+      msg.AppendLiteral(" : ");
+    }
+  }
+  msg.AppendLiteral("Unable to run script because scripts are blocked internally.");
+
+  LogSimpleConsoleError(msg, "DOM");
+}
+
+/* static */
+void
+nsContentUtils::AddScriptRunner(already_AddRefed<nsIRunnable> aRunnable)
+{
+  nsCOMPtr<nsIRunnable> runnable = aRunnable;
+  if (!runnable) {
+    return;
+  }
+
+  if (sScriptBlockerCount) {
+    sBlockedScriptRunners->AppendElement(runnable.forget());
+    return;
+  }
+
+  runnable->Run();
+}
+
+/* static */
+void
+nsContentUtils::AddScriptRunner(nsIRunnable* aRunnable) {
+  nsCOMPtr<nsIRunnable> runnable = aRunnable;
+  AddScriptRunner(runnable.forget());
+}
+
+/* static */
+void
+nsContentUtils::RunInStableState(already_AddRefed<nsIRunnable> aRunnable)
+{
+  MOZ_ASSERT(CycleCollectedJSContext::Get(), "Must be on a script thread!");
+  CycleCollectedJSContext::Get()->RunInStableState(Move(aRunnable));
+}
+
+/* static */
+void
+nsContentUtils::RunInMetastableState(already_AddRefed<nsIRunnable> aRunnable)
+{
+  MOZ_ASSERT(CycleCollectedJSContext::Get(), "Must be on a script thread!");
+  CycleCollectedJSContext::Get()->RunInMetastableState(Move(aRunnable));
+}
+
+void
+nsContentUtils::EnterMicroTask()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  ++sMicroTaskLevel;
+}
+
+void
+nsContentUtils::LeaveMicroTask()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (--sMicroTaskLevel == 0) {
+    PerformMainThreadMicroTaskCheckpoint();
+  }
+}
+
+bool
+nsContentUtils::IsInMicroTask()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return sMicroTaskLevel != 0;
+}
+
+uint32_t
+nsContentUtils::MicroTaskLevel()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return sMicroTaskLevel;
+}
+
+void
+nsContentUtils::SetMicroTaskLevel(uint32_t aLevel)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  sMicroTaskLevel = aLevel;
+}
+
+void
+nsContentUtils::PerformMainThreadMicroTaskCheckpoint()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsDOMMutationObserver::HandleMutations();
+}
+
+/*
+ * Helper function for nsContentUtils::ProcessViewportInfo.
+ *
+ * Handles a single key=value pair. If it corresponds to a valid viewport
+ * attribute, add it to the document header data. No validation is done on the
+ * value itself (this is done at display time).
+ */
+static void ProcessViewportToken(nsIDocument *aDocument,
+                                 const nsAString &token) {
+
+  /* Iterators. */
+  nsAString::const_iterator tip, tail, end;
+  token.BeginReading(tip);
+  tail = tip;
+  token.EndReading(end);
+
+  /* Move tip to the '='. */
+  while ((tip != end) && (*tip != '='))
+    ++tip;
+
+  /* If we didn't find an '=', punt. */
+  if (tip == end)
+    return;
+
+  /* Extract the key and value. */
+  const nsAString &key =
+    nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(Substring(tail, tip),
+                                                        true);
+  const nsAString &value =
+    nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(Substring(++tip, end),
+                                                        true);
+
+  /* Check for known keys. If we find a match, insert the appropriate
+   * information into the document header. */
+  nsCOMPtr<nsIAtom> key_atom = NS_Atomize(key);
+  if (key_atom == nsGkAtoms::height)
+    aDocument->SetHeaderData(nsGkAtoms::viewport_height, value);
+  else if (key_atom == nsGkAtoms::width)
+    aDocument->SetHeaderData(nsGkAtoms::viewport_width, value);
+  else if (key_atom == nsGkAtoms::initial_scale)
+    aDocument->SetHeaderData(nsGkAtoms::viewport_initial_scale, value);
+  else if (key_atom == nsGkAtoms::minimum_scale)
+    aDocument->SetHeaderData(nsGkAtoms::viewport_minimum_scale, value);
+  else if (key_atom == nsGkAtoms::maximum_scale)
+    aDocument->SetHeaderData(nsGkAtoms::viewport_maximum_scale, value);
+  else if (key_atom == nsGkAtoms::user_scalable)
+    aDocument->SetHeaderData(nsGkAtoms::viewport_user_scalable, value);
+}
+
+#define IS_SEPARATOR(c) ((c == '=') || (c == ',') || (c == ';') || \
+                         (c == '\t') || (c == '\n') || (c == '\r'))
+
+/* static */
+nsresult
+nsContentUtils::ProcessViewportInfo(nsIDocument *aDocument,
+                                    const nsAString &viewportInfo) {
+
+  /* We never fail. */
+  nsresult rv = NS_OK;
+
+  aDocument->SetHeaderData(nsGkAtoms::viewport, viewportInfo);
+
+  /* Iterators. */
+  nsAString::const_iterator tip, tail, end;
+  viewportInfo.BeginReading(tip);
+  tail = tip;
+  viewportInfo.EndReading(end);
+
+  /* Read the tip to the first non-separator character. */
+  while ((tip != end) && (IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip)))
+    ++tip;
+
+  /* Read through and find tokens separated by separators. */
+  while (tip != end) {
+
+    /* Synchronize tip and tail. */
+    tail = tip;
+
+    /* Advance tip past non-separator characters. */
+    while ((tip != end) && !IS_SEPARATOR(*tip))
+      ++tip;
+
+    /* Allow white spaces that surround the '=' character */
+    if ((tip != end) && (*tip == '=')) {
+      ++tip;
+
+      while ((tip != end) && nsCRT::IsAsciiSpace(*tip))
+        ++tip;
+
+      while ((tip != end) && !(IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip)))
+        ++tip;
+    }
+
+    /* Our token consists of the characters between tail and tip. */
+    ProcessViewportToken(aDocument, Substring(tail, tip));
+
+    /* Skip separators. */
+    while ((tip != end) && (IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip)))
+      ++tip;
+  }
+
+  return rv;
+
+}
+
+#undef IS_SEPARATOR
+
+/* static */
+void
+nsContentUtils::HidePopupsInDocument(nsIDocument* aDocument)
+{
+#ifdef MOZ_XUL
+  nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
+  if (pm && aDocument) {
+    nsCOMPtr<nsIDocShellTreeItem> docShellToHide = aDocument->GetDocShell();
+    if (docShellToHide)
+      pm->HidePopupsInDocShell(docShellToHide);
+  }
+#endif
+}
+
+/* static */
+already_AddRefed<nsIDragSession>
+nsContentUtils::GetDragSession()
+{
+  nsCOMPtr<nsIDragSession> dragSession;
+  nsCOMPtr<nsIDragService> dragService =
+    do_GetService("@mozilla.org/widget/dragservice;1");
+  if (dragService)
+    dragService->GetCurrentSession(getter_AddRefs(dragSession));
+  return dragSession.forget();
+}
+
+/* static */
+nsresult
+nsContentUtils::SetDataTransferInEvent(WidgetDragEvent* aDragEvent)
+{
+  if (aDragEvent->mDataTransfer || !aDragEvent->IsTrusted()) {
+    return NS_OK;
+  }
+
+  // For dragstart events, the data transfer object is
+  // created before the event fires, so it should already be set. For other
+  // drag events, get the object from the drag session.
+  NS_ASSERTION(aDragEvent->mMessage != eDragStart,
+               "draggesture event created without a dataTransfer");
+
+  nsCOMPtr<nsIDragSession> dragSession = GetDragSession();
+  NS_ENSURE_TRUE(dragSession, NS_OK); // no drag in progress
+
+  nsCOMPtr<nsIDOMDataTransfer> dataTransfer;
+  nsCOMPtr<DataTransfer> initialDataTransfer;
+  dragSession->GetDataTransfer(getter_AddRefs(dataTransfer));
+  if (dataTransfer) {
+    initialDataTransfer = do_QueryInterface(dataTransfer);
+    if (!initialDataTransfer) {
+      return NS_ERROR_FAILURE;
+    }
+  } else {
+    // A dataTransfer won't exist when a drag was started by some other
+    // means, for instance calling the drag service directly, or a drag
+    // from another application. In either case, a new dataTransfer should
+    // be created that reflects the data.
+    initialDataTransfer =
+      new DataTransfer(aDragEvent->mTarget, aDragEvent->mMessage, true, -1);
+
+    // now set it in the drag session so we don't need to create it again
+    dragSession->SetDataTransfer(initialDataTransfer);
+  }
+
+  bool isCrossDomainSubFrameDrop = false;
+  if (aDragEvent->mMessage == eDrop) {
+    isCrossDomainSubFrameDrop = CheckForSubFrameDrop(dragSession, aDragEvent);
+  }
+
+  // each event should use a clone of the original dataTransfer.
+  initialDataTransfer->Clone(aDragEvent->mTarget, aDragEvent->mMessage,
+                             aDragEvent->mUserCancelled,
+                             isCrossDomainSubFrameDrop,
+                             getter_AddRefs(aDragEvent->mDataTransfer));
+  if (NS_WARN_IF(!aDragEvent->mDataTransfer)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  // for the dragenter and dragover events, initialize the drop effect
+  // from the drop action, which platform specific widget code sets before
+  // the event is fired based on the keyboard state.
+  if (aDragEvent->mMessage == eDragEnter || aDragEvent->mMessage == eDragOver) {
+    uint32_t action, effectAllowed;
+    dragSession->GetDragAction(&action);
+    aDragEvent->mDataTransfer->GetEffectAllowedInt(&effectAllowed);
+    aDragEvent->mDataTransfer->SetDropEffectInt(
+                                 FilterDropEffect(action, effectAllowed));
+  }
+  else if (aDragEvent->mMessage == eDrop ||
+           aDragEvent->mMessage == eDragEnd) {
+    // For the drop and dragend events, set the drop effect based on the
+    // last value that the dropEffect had. This will have been set in
+    // EventStateManager::PostHandleEvent for the last dragenter or
+    // dragover event.
+    uint32_t dropEffect;
+    initialDataTransfer->GetDropEffectInt(&dropEffect);
+    aDragEvent->mDataTransfer->SetDropEffectInt(dropEffect);
+  }
+
+  return NS_OK;
+}
+
+/* static */
+uint32_t
+nsContentUtils::FilterDropEffect(uint32_t aAction, uint32_t aEffectAllowed)
+{
+  // It is possible for the drag action to include more than one action, but
+  // the widget code which sets the action from the keyboard state should only
+  // be including one. If multiple actions were set, we just consider them in
+  //  the following order:
+  //   copy, link, move
+  if (aAction & nsIDragService::DRAGDROP_ACTION_COPY)
+    aAction = nsIDragService::DRAGDROP_ACTION_COPY;
+  else if (aAction & nsIDragService::DRAGDROP_ACTION_LINK)
+    aAction = nsIDragService::DRAGDROP_ACTION_LINK;
+  else if (aAction & nsIDragService::DRAGDROP_ACTION_MOVE)
+    aAction = nsIDragService::DRAGDROP_ACTION_MOVE;
+
+  // Filter the action based on the effectAllowed. If the effectAllowed
+  // doesn't include the action, then that action cannot be done, so adjust
+  // the action to something that is allowed. For a copy, adjust to move or
+  // link. For a move, adjust to copy or link. For a link, adjust to move or
+  // link. Otherwise, use none.
+  if (aAction & aEffectAllowed ||
+      aEffectAllowed == nsIDragService::DRAGDROP_ACTION_UNINITIALIZED)
+    return aAction;
+  if (aEffectAllowed & nsIDragService::DRAGDROP_ACTION_MOVE)
+    return nsIDragService::DRAGDROP_ACTION_MOVE;
+  if (aEffectAllowed & nsIDragService::DRAGDROP_ACTION_COPY)
+    return nsIDragService::DRAGDROP_ACTION_COPY;
+  if (aEffectAllowed & nsIDragService::DRAGDROP_ACTION_LINK)
+    return nsIDragService::DRAGDROP_ACTION_LINK;
+  return nsIDragService::DRAGDROP_ACTION_NONE;
+}
+
+/* static */
+bool
+nsContentUtils::CheckForSubFrameDrop(nsIDragSession* aDragSession,
+                                     WidgetDragEvent* aDropEvent)
+{
+  nsCOMPtr<nsIContent> target = do_QueryInterface(aDropEvent->mOriginalTarget);
+  if (!target) {
+    return true;
+  }
+
+  nsIDocument* targetDoc = target->OwnerDoc();
+  nsPIDOMWindowOuter* targetWin = targetDoc->GetWindow();
+  if (!targetWin) {
+    return true;
+  }
+
+  nsCOMPtr<nsIDocShellTreeItem> tdsti = targetWin->GetDocShell();
+  if (!tdsti) {
+    return true;
+  }
+
+  // Always allow dropping onto chrome shells.
+  if (tdsti->ItemType() == nsIDocShellTreeItem::typeChrome) {
+    return false;
+  }
+
+  // If there is no source node, then this is a drag from another
+  // application, which should be allowed.
+  nsCOMPtr<nsIDOMDocument> sourceDocument;
+  aDragSession->GetSourceDocument(getter_AddRefs(sourceDocument));
+  nsCOMPtr<nsIDocument> doc = do_QueryInterface(sourceDocument);
+  if (doc) {
+    // Get each successive parent of the source document and compare it to
+    // the drop document. If they match, then this is a drag from a child frame.
+    do {
+      doc = doc->GetParentDocument();
+      if (doc == targetDoc) {
+        // The drag is from a child frame.
+        return true;
+      }
+    } while (doc);
+  }
+
+  return false;
+}
+
+/* static */
+bool
+nsContentUtils::URIIsLocalFile(nsIURI *aURI)
+{
+  bool isFile;
+  nsCOMPtr<nsINetUtil> util = do_QueryInterface(sIOService);
+
+  // Important: we do NOT test the entire URI chain here!
+  return util && NS_SUCCEEDED(util->ProtocolHasFlags(aURI,
+                                nsIProtocolHandler::URI_IS_LOCAL_FILE,
+                                &isFile)) &&
+         isFile;
+}
+
+/* static */
+nsIScriptContext*
+nsContentUtils::GetContextForEventHandlers(nsINode* aNode,
+                                           nsresult* aRv)
+{
+  *aRv = NS_OK;
+  bool hasHadScriptObject = true;
+  nsIScriptGlobalObject* sgo =
+    aNode->OwnerDoc()->GetScriptHandlingObject(hasHadScriptObject);
+  // It is bad if the document doesn't have event handling context,
+  // but it used to have one.
+  if (!sgo && hasHadScriptObject) {
+    *aRv = NS_ERROR_UNEXPECTED;
+    return nullptr;
+  }
+
+  if (sgo) {
+    nsIScriptContext* scx = sgo->GetContext();
+    // Bad, no context from script global object!
+    if (!scx) {
+      *aRv = NS_ERROR_UNEXPECTED;
+      return nullptr;
+    }
+    return scx;
+  }
+
+  return nullptr;
+}
+
+/* static */
+JSContext *
+nsContentUtils::GetCurrentJSContext()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(IsInitialized());
+  if (!IsJSAPIActive()) {
+    return nullptr;
+  }
+  return danger::GetJSContext();
+}
+
+/* static */
+JSContext *
+nsContentUtils::GetCurrentJSContextForThread()
+{
+  MOZ_ASSERT(IsInitialized());
+  if (MOZ_LIKELY(NS_IsMainThread())) {
+    return GetCurrentJSContext();
+  } else {
+    return workers::GetCurrentThreadJSContext();
+  }
+}
+
+template<typename StringType, typename CharType>
+void
+_ASCIIToLowerInSitu(StringType& aStr)
+{
+  CharType* iter = aStr.BeginWriting();
+  CharType* end = aStr.EndWriting();
+  MOZ_ASSERT(iter && end);
+
+  while (iter != end) {
+    CharType c = *iter;
+    if (c >= 'A' && c <= 'Z') {
+      *iter = c + ('a' - 'A');
+    }
+    ++iter;
+  }
+}
+
+/* static */
+void
+nsContentUtils::ASCIIToLower(nsAString& aStr)
+{
+  return _ASCIIToLowerInSitu<nsAString, char16_t>(aStr);
+}
+
+/* static */
+void
+nsContentUtils::ASCIIToLower(nsACString& aStr)
+{
+  return _ASCIIToLowerInSitu<nsACString, char>(aStr);
+}
+
+template<typename StringType, typename CharType>
+void
+_ASCIIToLowerCopy(const StringType& aSource, StringType& aDest)
+{
+  uint32_t len = aSource.Length();
+  aDest.SetLength(len);
+  MOZ_ASSERT(aDest.Length() == len);
+
+  CharType* dest = aDest.BeginWriting();
+  MOZ_ASSERT(dest);
+
+  const CharType* iter = aSource.BeginReading();
+  const CharType* end = aSource.EndReading();
+  while (iter != end) {
+    CharType c = *iter;
+    *dest = (c >= 'A' && c <= 'Z') ?
+       c + ('a' - 'A') : c;
+    ++iter;
+    ++dest;
+  }
+}
+
+/* static */
+void
+nsContentUtils::ASCIIToLower(const nsAString& aSource, nsAString& aDest) {
+  return _ASCIIToLowerCopy<nsAString, char16_t>(aSource, aDest);
+}
+
+/* static */
+void
+nsContentUtils::ASCIIToLower(const nsACString& aSource, nsACString& aDest) {
+  return _ASCIIToLowerCopy<nsACString, char>(aSource, aDest);
+}
+
+
+template<typename StringType, typename CharType>
+void
+_ASCIIToUpperInSitu(StringType& aStr)
+{
+  CharType* iter = aStr.BeginWriting();
+  CharType* end = aStr.EndWriting();
+  MOZ_ASSERT(iter && end);
+
+  while (iter != end) {
+    CharType c = *iter;
+    if (c >= 'a' && c <= 'z') {
+      *iter = c + ('A' - 'a');
+    }
+    ++iter;
+  }
+}
+
+/* static */
+void
+nsContentUtils::ASCIIToUpper(nsAString& aStr)
+{
+  return _ASCIIToUpperInSitu<nsAString, char16_t>(aStr);
+}
+
+/* static */
+void
+nsContentUtils::ASCIIToUpper(nsACString& aStr)
+{
+  return _ASCIIToUpperInSitu<nsACString, char>(aStr);
+}
+
+template<typename StringType, typename CharType>
+void
+_ASCIIToUpperCopy(const StringType& aSource, StringType& aDest)
+{
+  uint32_t len = aSource.Length();
+  aDest.SetLength(len);
+  MOZ_ASSERT(aDest.Length() == len);
+
+  CharType* dest = aDest.BeginWriting();
+  MOZ_ASSERT(dest);
+
+  const CharType* iter = aSource.BeginReading();
+  const CharType* end = aSource.EndReading();
+  while (iter != end) {
+    CharType c = *iter;
+    *dest = (c >= 'a' && c <= 'z') ?
+      c + ('A' - 'a') : c;
+    ++iter;
+    ++dest;
+  }
+}
+
+/* static */
+void
+nsContentUtils::ASCIIToUpper(const nsAString& aSource, nsAString& aDest)
+{
+  return _ASCIIToUpperCopy<nsAString, char16_t>(aSource, aDest);
+}
+
+/* static */
+void
+nsContentUtils::ASCIIToUpper(const nsACString& aSource, nsACString& aDest)
+{
+  return _ASCIIToUpperCopy<nsACString, char>(aSource, aDest);
+}
+
+/* static */
+bool
+nsContentUtils::EqualsIgnoreASCIICase(const nsAString& aStr1,
+                                      const nsAString& aStr2)
+{
+  uint32_t len = aStr1.Length();
+  if (len != aStr2.Length()) {
+    return false;
+  }
+
+  const char16_t* str1 = aStr1.BeginReading();
+  const char16_t* str2 = aStr2.BeginReading();
+  const char16_t* end = str1 + len;
+
+  while (str1 < end) {
+    char16_t c1 = *str1++;
+    char16_t c2 = *str2++;
+
+    // First check if any bits other than the 0x0020 differs
+    if ((c1 ^ c2) & 0xffdf) {
+      return false;
+    }
+
+    // We know they can only differ in the 0x0020 bit.
+    // Likely the two chars are the same, so check that first
+    if (c1 != c2) {
+      // They do differ, but since it's only in the 0x0020 bit, check if it's
+      // the same ascii char, but just differing in case
+      char16_t c1Upper = c1 & 0xffdf;
+      if (!('A' <= c1Upper && c1Upper <= 'Z')) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+/* static */
+bool
+nsContentUtils::StringContainsASCIIUpper(const nsAString& aStr)
+{
+  const char16_t* iter = aStr.BeginReading();
+  const char16_t* end = aStr.EndReading();
+  while (iter != end) {
+    char16_t c = *iter;
+    if (c >= 'A' && c <= 'Z') {
+      return true;
+    }
+    ++iter;
+  }
+
+  return false;
+}
+
+/* static */
+nsIInterfaceRequestor*
+nsContentUtils::SameOriginChecker()
+{
+  if (!sSameOriginChecker) {
+    sSameOriginChecker = new SameOriginCheckerImpl();
+    NS_ADDREF(sSameOriginChecker);
+  }
+  return sSameOriginChecker;
+}
+
+/* static */
+nsresult
+nsContentUtils::CheckSameOrigin(nsIChannel *aOldChannel, nsIChannel *aNewChannel)
+{
+  if (!nsContentUtils::GetSecurityManager())
+    return NS_ERROR_NOT_AVAILABLE;
+
+  nsCOMPtr<nsIPrincipal> oldPrincipal;
+  nsContentUtils::GetSecurityManager()->
+    GetChannelResultPrincipal(aOldChannel, getter_AddRefs(oldPrincipal));
+
+  nsCOMPtr<nsIURI> newURI;
+  aNewChannel->GetURI(getter_AddRefs(newURI));
+  nsCOMPtr<nsIURI> newOriginalURI;
+  aNewChannel->GetOriginalURI(getter_AddRefs(newOriginalURI));
+
+  NS_ENSURE_STATE(oldPrincipal && newURI && newOriginalURI);
+
+  nsresult rv = oldPrincipal->CheckMayLoad(newURI, false, false);
+  if (NS_SUCCEEDED(rv) && newOriginalURI != newURI) {
+    rv = oldPrincipal->CheckMayLoad(newOriginalURI, false, false);
+  }
+
+  return rv;
+}
+
+NS_IMPL_ISUPPORTS(SameOriginCheckerImpl,
+                  nsIChannelEventSink,
+                  nsIInterfaceRequestor)
+
+NS_IMETHODIMP
+SameOriginCheckerImpl::AsyncOnChannelRedirect(nsIChannel* aOldChannel,
+                                              nsIChannel* aNewChannel,
+                                              uint32_t aFlags,
+                                              nsIAsyncVerifyRedirectCallback* cb)
+{
+  NS_PRECONDITION(aNewChannel, "Redirecting to null channel?");
+
+  nsresult rv = nsContentUtils::CheckSameOrigin(aOldChannel, aNewChannel);
+  if (NS_SUCCEEDED(rv)) {
+    cb->OnRedirectVerifyCallback(NS_OK);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+SameOriginCheckerImpl::GetInterface(const nsIID& aIID, void** aResult)
+{
+  return QueryInterface(aIID, aResult);
+}
+
+/* static */
+nsresult
+nsContentUtils::GetASCIIOrigin(nsIPrincipal* aPrincipal, nsACString& aOrigin)
+{
+  NS_PRECONDITION(aPrincipal, "missing principal");
+
+  aOrigin.Truncate();
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = aPrincipal->GetURI(getter_AddRefs(uri));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (uri) {
+    return GetASCIIOrigin(uri, aOrigin);
+  }
+
+  aOrigin.AssignLiteral("null");
+
+  return NS_OK;
+}
+
+/* static */
+nsresult
+nsContentUtils::GetASCIIOrigin(nsIURI* aURI, nsACString& aOrigin)
+{
+  NS_PRECONDITION(aURI, "missing uri");
+
+  // For Blob URI we have to return the origin of page using its principal.
+  nsCOMPtr<nsIURIWithPrincipal> uriWithPrincipal = do_QueryInterface(aURI);
+  if (uriWithPrincipal) {
+    nsCOMPtr<nsIPrincipal> principal;
+    uriWithPrincipal->GetPrincipal(getter_AddRefs(principal));
+
+    if (principal) {
+      nsCOMPtr<nsIURI> uri;
+      nsresult rv = principal->GetURI(getter_AddRefs(uri));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      if (uri && uri != aURI) {
+        return GetASCIIOrigin(uri, aOrigin);
+      }
+    }
+  }
+
+  aOrigin.Truncate();
+
+  nsCOMPtr<nsIURI> uri = NS_GetInnermostURI(aURI);
+  NS_ENSURE_TRUE(uri, NS_ERROR_UNEXPECTED);
+
+  nsCString host;
+  nsresult rv = uri->GetAsciiHost(host);
+
+  if (NS_SUCCEEDED(rv) && !host.IsEmpty()) {
+    nsCString scheme;
+    rv = uri->GetScheme(scheme);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    int32_t port = -1;
+    uri->GetPort(&port);
+    if (port != -1 && port == NS_GetDefaultPort(scheme.get()))
+      port = -1;
+
+    nsCString hostPort;
+    rv = NS_GenerateHostPort(host, port, hostPort);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aOrigin = scheme + NS_LITERAL_CSTRING("://") + hostPort;
+  }
+  else {
+    aOrigin.AssignLiteral("null");
+  }
+
+  return NS_OK;
+}
+
+/* static */
+nsresult
+nsContentUtils::GetUTFOrigin(nsIPrincipal* aPrincipal, nsAString& aOrigin)
+{
+  NS_PRECONDITION(aPrincipal, "missing principal");
+
+  aOrigin.Truncate();
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = aPrincipal->GetURI(getter_AddRefs(uri));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (uri) {
+    return GetUTFOrigin(uri, aOrigin);
+  }
+
+  aOrigin.AssignLiteral("null");
+
+  return NS_OK;
+}
+
+/* static */
+nsresult
+nsContentUtils::GetUTFOrigin(nsIURI* aURI, nsAString& aOrigin)
+{
+  NS_PRECONDITION(aURI, "missing uri");
+
+  // For Blob URI we have to return the origin of page using its principal.
+  nsCOMPtr<nsIURIWithPrincipal> uriWithPrincipal = do_QueryInterface(aURI);
+  if (uriWithPrincipal) {
+    nsCOMPtr<nsIPrincipal> principal;
+    uriWithPrincipal->GetPrincipal(getter_AddRefs(principal));
+
+    if (principal) {
+      nsCOMPtr<nsIURI> uri;
+      nsresult rv = principal->GetURI(getter_AddRefs(uri));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      if (uri && uri != aURI) {
+        return GetUTFOrigin(uri, aOrigin);
+      }
+    } else {
+      // We are probably dealing with an unknown blob URL.
+      bool isBlobURL = false;
+      nsresult rv = aURI->SchemeIs(BLOBURI_SCHEME, &isBlobURL);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      if (isBlobURL) {
+        nsAutoCString path;
+        rv = aURI->GetPath(path);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        nsCOMPtr<nsIURI> uri;
+        nsresult rv = NS_NewURI(getter_AddRefs(uri), path);
+        if (NS_FAILED(rv)) {
+          aOrigin.AssignLiteral("null");
+          return NS_OK;
+        }
+
+        return GetUTFOrigin(uri, aOrigin);
+      }
+    }
+  }
+
+  aOrigin.Truncate();
+
+  nsCOMPtr<nsIURI> uri = NS_GetInnermostURI(aURI);
+  NS_ENSURE_TRUE(uri, NS_ERROR_UNEXPECTED);
+
+  nsCString host;
+  nsresult rv = uri->GetHost(host);
+
+  if (NS_SUCCEEDED(rv) && !host.IsEmpty()) {
+    nsCString scheme;
+    rv = uri->GetScheme(scheme);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    int32_t port = -1;
+    uri->GetPort(&port);
+    if (port != -1 && port == NS_GetDefaultPort(scheme.get()))
+      port = -1;
+
+    nsCString hostPort;
+    rv = NS_GenerateHostPort(host, port, hostPort);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aOrigin = NS_ConvertUTF8toUTF16(
+      scheme + NS_LITERAL_CSTRING("://") + hostPort);
+  }
+  else {
+    aOrigin.AssignLiteral("null");
+  }
+
+  return NS_OK;
+}
+
+/* static */
+bool
+nsContentUtils::CheckMayLoad(nsIPrincipal* aPrincipal, nsIChannel* aChannel, bool aAllowIfInheritsPrincipal)
+{
+  nsCOMPtr<nsIURI> channelURI;
+  nsresult rv = NS_GetFinalChannelURI(aChannel, getter_AddRefs(channelURI));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return NS_SUCCEEDED(aPrincipal->CheckMayLoad(channelURI, false, aAllowIfInheritsPrincipal));
+}
+
+nsContentTypeParser::nsContentTypeParser(const nsAString& aString)
+  : mString(aString), mService(nullptr)
+{
+  CallGetService("@mozilla.org/network/mime-hdrparam;1", &mService);
+}
+
+nsContentTypeParser::~nsContentTypeParser()
+{
+  NS_IF_RELEASE(mService);
+}
+
+nsresult
+nsContentTypeParser::GetParameter(const char* aParameterName,
+                                  nsAString& aResult) const
+{
+  NS_ENSURE_TRUE(mService, NS_ERROR_FAILURE);
+  return mService->GetParameterHTTP(mString, aParameterName,
+                                    EmptyCString(), false, nullptr,
+                                    aResult);
+}
+
+nsresult
+nsContentTypeParser::GetType(nsAString& aResult) const
+{
+  nsresult rv = GetParameter(nullptr, aResult);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsContentUtils::ASCIIToLower(aResult);
+  return NS_OK;
+}
+
+/* static */
+
+bool
+nsContentUtils::CanAccessNativeAnon()
+{
+  return LegacyIsCallerChromeOrNativeCode() || IsCallerContentXBL();
+}
+
+/* static */ nsresult
+nsContentUtils::DispatchXULCommand(nsIContent* aTarget,
+                                   bool aTrusted,
+                                   nsIDOMEvent* aSourceEvent,
+                                   nsIPresShell* aShell,
+                                   bool aCtrl,
+                                   bool aAlt,
+                                   bool aShift,
+                                   bool aMeta)
+{
+  NS_ENSURE_STATE(aTarget);
+  nsIDocument* doc = aTarget->OwnerDoc();
+  nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(doc);
+  NS_ENSURE_STATE(domDoc);
+  nsCOMPtr<nsIDOMEvent> event;
+  domDoc->CreateEvent(NS_LITERAL_STRING("xulcommandevent"),
+                      getter_AddRefs(event));
+  nsCOMPtr<nsIDOMXULCommandEvent> xulCommand = do_QueryInterface(event);
+  nsresult rv = xulCommand->InitCommandEvent(NS_LITERAL_STRING("command"),
+                                             true, true, doc->GetInnerWindow(),
+                                             0, aCtrl, aAlt, aShift, aMeta,
+                                             aSourceEvent);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aShell) {
+    nsEventStatus status = nsEventStatus_eIgnore;
+    nsCOMPtr<nsIPresShell> kungFuDeathGrip = aShell;
+    return aShell->HandleDOMEventWithTarget(aTarget, event, &status);
+  }
+
+  nsCOMPtr<EventTarget> target = do_QueryInterface(aTarget);
+  NS_ENSURE_STATE(target);
+  bool dummy;
+  return target->DispatchEvent(event, &dummy);
+}
+
+// static
+nsresult
+nsContentUtils::WrapNative(JSContext *cx, nsISupports *native,
+                           nsWrapperCache *cache, const nsIID* aIID,
+                           JS::MutableHandle<JS::Value> vp, bool aAllowWrapping)
+{
+  MOZ_ASSERT(cx == GetCurrentJSContext());
+
+  if (!native) {
+    vp.setNull();
+
+    return NS_OK;
+  }
+
+  JSObject *wrapper = xpc_FastGetCachedWrapper(cx, cache, vp);
+  if (wrapper) {
+    return NS_OK;
+  }
+
+  NS_ENSURE_TRUE(sXPConnect, NS_ERROR_UNEXPECTED);
+
+  if (!NS_IsMainThread()) {
+    MOZ_CRASH();
+  }
+
+  nsresult rv = NS_OK;
+  JS::Rooted<JSObject*> scope(cx, JS::CurrentGlobalOrNull(cx));
+  rv = sXPConnect->WrapNativeToJSVal(cx, scope, native, cache, aIID,
+                                     aAllowWrapping, vp);
+  return rv;
+}
+
+nsresult
+nsContentUtils::CreateArrayBuffer(JSContext *aCx, const nsACString& aData,
+                                  JSObject** aResult)
+{
+  if (!aCx) {
+    return NS_ERROR_FAILURE;
+  }
+
+  int32_t dataLen = aData.Length();
+  *aResult = JS_NewArrayBuffer(aCx, dataLen);
+  if (!*aResult) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (dataLen > 0) {
+    NS_ASSERTION(JS_IsArrayBufferObject(*aResult), "What happened?");
+    JS::AutoCheckCannotGC nogc;
+    bool isShared;
+    memcpy(JS_GetArrayBufferData(*aResult, &isShared, nogc), aData.BeginReading(), dataLen);
+    MOZ_ASSERT(!isShared);
+  }
+
+  return NS_OK;
+}
+
+void
+nsContentUtils::StripNullChars(const nsAString& aInStr, nsAString& aOutStr)
+{
+  // In common cases where we don't have nulls in the
+  // string we can simple simply bypass the checking code.
+  int32_t firstNullPos = aInStr.FindChar('\0');
+  if (firstNullPos == kNotFound) {
+    aOutStr.Assign(aInStr);
+    return;
+  }
+
+  aOutStr.SetCapacity(aInStr.Length() - 1);
+  nsAString::const_iterator start, end;
+  aInStr.BeginReading(start);
+  aInStr.EndReading(end);
+  while (start != end) {
+    if (*start != '\0')
+      aOutStr.Append(*start);
+    ++start;
+  }
+}
+
+struct ClassMatchingInfo {
+  nsAttrValue::AtomArray mClasses;
+  nsCaseTreatment mCaseTreatment;
+};
+
+// static
+bool
+nsContentUtils::MatchClassNames(nsIContent* aContent, int32_t aNamespaceID,
+                                nsIAtom* aAtom, void* aData)
+{
+  // We can't match if there are no class names
+  const nsAttrValue* classAttr = aContent->GetClasses();
+  if (!classAttr) {
+    return false;
+  }
+
+  // need to match *all* of the classes
+  ClassMatchingInfo* info = static_cast<ClassMatchingInfo*>(aData);
+  uint32_t length = info->mClasses.Length();
+  if (!length) {
+    // If we actually had no classes, don't match.
+    return false;
+  }
+  uint32_t i;
+  for (i = 0; i < length; ++i) {
+    if (!classAttr->Contains(info->mClasses[i],
+                             info->mCaseTreatment)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+// static
+void
+nsContentUtils::DestroyClassNameArray(void* aData)
+{
+  ClassMatchingInfo* info = static_cast<ClassMatchingInfo*>(aData);
+  delete info;
+}
+
+// static
+void*
+nsContentUtils::AllocClassMatchingInfo(nsINode* aRootNode,
+                                       const nsString* aClasses)
+{
+  nsAttrValue attrValue;
+  attrValue.ParseAtomArray(*aClasses);
+  // nsAttrValue::Equals is sensitive to order, so we'll send an array
+  ClassMatchingInfo* info = new ClassMatchingInfo;
+  if (attrValue.Type() == nsAttrValue::eAtomArray) {
+    info->mClasses.SwapElements(*(attrValue.GetAtomArrayValue()));
+  } else if (attrValue.Type() == nsAttrValue::eAtom) {
+    info->mClasses.AppendElement(attrValue.GetAtomValue());
+  }
+
+  info->mCaseTreatment =
+    aRootNode->OwnerDoc()->GetCompatibilityMode() == eCompatibility_NavQuirks ?
+    eIgnoreCase : eCaseMatters;
+  return info;
+}
+
+// static
+bool
+nsContentUtils::IsFocusedContent(const nsIContent* aContent)
+{
+  nsFocusManager* fm = nsFocusManager::GetFocusManager();
+
+  return fm && fm->GetFocusedContent() == aContent;
+}
+
+bool
+nsContentUtils::IsSubDocumentTabbable(nsIContent* aContent)
+{
+  //XXXsmaug Shadow DOM spec issue!
+  //         We may need to change this to GetComposedDoc().
+  nsIDocument* doc = aContent->GetUncomposedDoc();
+  if (!doc) {
+    return false;
+  }
+
+  // If the subdocument lives in another process, the frame is
+  // tabbable.
+  if (EventStateManager::IsRemoteTarget(aContent)) {
+    return true;
+  }
+
+  // XXXbz should this use OwnerDoc() for GetSubDocumentFor?
+  // sXBL/XBL2 issue!
+  nsIDocument* subDoc = doc->GetSubDocumentFor(aContent);
+  if (!subDoc) {
+    return false;
+  }
+
+  nsCOMPtr<nsIDocShell> docShell = subDoc->GetDocShell();
+  if (!docShell) {
+    return false;
+  }
+
+  nsCOMPtr<nsIContentViewer> contentViewer;
+  docShell->GetContentViewer(getter_AddRefs(contentViewer));
+  if (!contentViewer) {
+    return false;
+  }
+
+  nsCOMPtr<nsIContentViewer> zombieViewer;
+  contentViewer->GetPreviousViewer(getter_AddRefs(zombieViewer));
+
+  // If there are 2 viewers for the current docshell, that
+  // means the current document is a zombie document.
+  // Only navigate into the subdocument if it's not a zombie.
+  return !zombieViewer;
+}
+
+bool
+nsContentUtils::IsUserFocusIgnored(nsINode* aNode)
+{
+  if (!nsGenericHTMLFrameElement::BrowserFramesEnabled()) {
+    return false;
+  }
+
+  // Check if our mozbrowser iframe ancestors has ignoreuserfocus attribute.
+  while (aNode) {
+    nsCOMPtr<nsIMozBrowserFrame> browserFrame = do_QueryInterface(aNode);
+    if (browserFrame &&
+        aNode->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::ignoreuserfocus) &&
+        browserFrame->GetReallyIsBrowserOrApp()) {
+      return true;
+    }
+    nsPIDOMWindowOuter* win = aNode->OwnerDoc()->GetWindow();
+    aNode = win ? win->GetFrameElementInternal() : nullptr;
+  }
+
+  return false;
+}
+
+bool
+nsContentUtils::HasScrollgrab(nsIContent* aContent)
+{
+  nsGenericHTMLElement* element = nsGenericHTMLElement::FromContentOrNull(aContent);
+  return element && element->Scrollgrab();
+}
+
+void
+nsContentUtils::FlushLayoutForTree(nsPIDOMWindowOuter* aWindow)
+{
+  if (!aWindow) {
+    return;
+  }
+
+  // Note that because FlushPendingNotifications flushes parents, this
+  // is O(N^2) in docshell tree depth.  However, the docshell tree is
+  // usually pretty shallow.
+
+  if (nsCOMPtr<nsIDocument> doc = aWindow->GetDoc()) {
+    doc->FlushPendingNotifications(Flush_Layout);
+  }
+
+  if (nsCOMPtr<nsIDocShell> docShell = aWindow->GetDocShell()) {
+    int32_t i = 0, i_end;
+    docShell->GetChildCount(&i_end);
+    for (; i < i_end; ++i) {
+      nsCOMPtr<nsIDocShellTreeItem> item;
+      docShell->GetChildAt(i, getter_AddRefs(item));
+      if (nsCOMPtr<nsPIDOMWindowOuter> win = item->GetWindow()) {
+        FlushLayoutForTree(win);
+      }
+    }
+  }
+}
+
+void nsContentUtils::RemoveNewlines(nsString &aString)
+{
+  // strip CR/LF and null
+  static const char badChars[] = {'\r', '\n', 0};
+  aString.StripChars(badChars);
+}
+
+void
+nsContentUtils::PlatformToDOMLineBreaks(nsString &aString)
+{
+  if (!PlatformToDOMLineBreaks(aString, fallible)) {
+    aString.AllocFailed(aString.Length());
+  }
+}
+
+bool
+nsContentUtils::PlatformToDOMLineBreaks(nsString& aString, const fallible_t& aFallible)
+{
+  if (aString.FindChar(char16_t('\r')) != -1) {
+    // Windows linebreaks: Map CRLF to LF:
+    if (!aString.ReplaceSubstring(u"\r\n", u"\n", aFallible)) {
+      return false;
+    }
+
+    // Mac linebreaks: Map any remaining CR to LF:
+    if (!aString.ReplaceSubstring(u"\r", u"\n", aFallible)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+void
+nsContentUtils::PopulateStringFromStringBuffer(nsStringBuffer* aBuf,
+                                               nsAString& aResultString)
+{
+  MOZ_ASSERT(aBuf, "Expecting a non-null string buffer");
+
+  uint32_t stringLen = NS_strlen(static_cast<char16_t*>(aBuf->Data()));
+
+  // SANITY CHECK: In case the nsStringBuffer isn't correctly
+  // null-terminated, let's clamp its length using the allocated size, to be
+  // sure the resulting string doesn't sample past the end of the the buffer.
+  // (Note that StorageSize() is in units of bytes, so we have to convert that
+  // to units of PRUnichars, and subtract 1 for the null-terminator.)
+  uint32_t allocStringLen = (aBuf->StorageSize() / sizeof(char16_t)) - 1;
+  MOZ_ASSERT(stringLen <= allocStringLen,
+             "string buffer lacks null terminator!");
+  stringLen = std::min(stringLen, allocStringLen);
+
+  aBuf->ToString(stringLen, aResultString);
+}
+
+nsIPresShell*
+nsContentUtils::FindPresShellForDocument(const nsIDocument* aDoc)
+{
+  const nsIDocument* doc = aDoc;
+  nsIDocument* displayDoc = doc->GetDisplayDocument();
+  if (displayDoc) {
+    doc = displayDoc;
+  }
+
+  nsIPresShell* shell = doc->GetShell();
+  if (shell) {
+    return shell;
+  }
+
+  nsCOMPtr<nsIDocShellTreeItem> docShellTreeItem = doc->GetDocShell();
+  while (docShellTreeItem) {
+    // We may be in a display:none subdocument, or we may not have a presshell
+    // created yet.
+    // Walk the docshell tree to find the nearest container that has a presshell,
+    // and return that.
+    nsCOMPtr<nsIDocShell> docShell = do_QueryInterface(docShellTreeItem);
+    nsIPresShell* presShell = docShell->GetPresShell();
+    if (presShell) {
+      return presShell;
+    }
+    nsCOMPtr<nsIDocShellTreeItem> parent;
+    docShellTreeItem->GetParent(getter_AddRefs(parent));
+    docShellTreeItem = parent;
+  }
+
+  return nullptr;
+}
+
+nsIWidget*
+nsContentUtils::WidgetForDocument(const nsIDocument* aDoc)
+{
+  nsIPresShell* shell = FindPresShellForDocument(aDoc);
+  if (shell) {
+    nsViewManager* VM = shell->GetViewManager();
+    if (VM) {
+      nsView* rootView = VM->GetRootView();
+      if (rootView) {
+        nsView* displayRoot = nsViewManager::GetDisplayRootFor(rootView);
+        if (displayRoot) {
+          return displayRoot->GetNearestWidget(nullptr);
+        }
+      }
+    }
+  }
+
+  return nullptr;
+}
+
+static already_AddRefed<LayerManager>
+LayerManagerForDocumentInternal(const nsIDocument *aDoc, bool aRequirePersistent)
+{
+  nsIWidget *widget = nsContentUtils::WidgetForDocument(aDoc);
+  if (widget) {
+    RefPtr<LayerManager> manager =
+      widget->GetLayerManager(aRequirePersistent ? nsIWidget::LAYER_MANAGER_PERSISTENT :
+                              nsIWidget::LAYER_MANAGER_CURRENT);
+    return manager.forget();
+  }
+
+  return nullptr;
+}
+
+already_AddRefed<LayerManager>
+nsContentUtils::LayerManagerForDocument(const nsIDocument *aDoc)
+{
+  return LayerManagerForDocumentInternal(aDoc, false);
+}
+
+already_AddRefed<LayerManager>
+nsContentUtils::PersistentLayerManagerForDocument(nsIDocument *aDoc)
+{
+  return LayerManagerForDocumentInternal(aDoc, true);
+}
+
+bool
+nsContentUtils::AllowXULXBLForPrincipal(nsIPrincipal* aPrincipal)
+{
+  if (IsSystemPrincipal(aPrincipal)) {
+    return true;
+  }
+
+  nsCOMPtr<nsIURI> princURI;
+  aPrincipal->GetURI(getter_AddRefs(princURI));
+
+  return princURI &&
+         ((sAllowXULXBL_for_file && SchemeIs(princURI, "file")) ||
+          IsSitePermAllow(aPrincipal, "allowXULXBL"));
+}
+
+bool
+nsContentUtils::IsPDFJSEnabled()
+{
+   nsCOMPtr<nsIStreamConverterService> convServ =
+     do_GetService("@mozilla.org/streamConverters;1");
+   nsresult rv = NS_ERROR_FAILURE;
+   bool canConvert = false;
+   if (convServ) {
+     rv = convServ->CanConvert("application/pdf", "text/html", &canConvert);
+   }
+   return NS_SUCCEEDED(rv) && canConvert;
+}
+
+bool
+nsContentUtils::IsSWFPlayerEnabled()
+{
+   nsCOMPtr<nsIStreamConverterService> convServ =
+     do_GetService("@mozilla.org/streamConverters;1");
+   nsresult rv = NS_ERROR_FAILURE;
+   bool canConvert = false;
+   if (convServ) {
+     rv = convServ->CanConvert("application/x-shockwave-flash",
+                               "text/html", &canConvert);
+   }
+   return NS_SUCCEEDED(rv) && canConvert;
+}
+
+already_AddRefed<nsIDocumentLoaderFactory>
+nsContentUtils::FindInternalContentViewer(const nsACString& aType,
+                                          ContentViewerType* aLoaderType)
+{
+  if (aLoaderType) {
+    *aLoaderType = TYPE_UNSUPPORTED;
+  }
+
+  // one helper factory, please
+  nsCOMPtr<nsICategoryManager> catMan(do_GetService(NS_CATEGORYMANAGER_CONTRACTID));
+  if (!catMan)
+    return nullptr;
+
+  nsCOMPtr<nsIDocumentLoaderFactory> docFactory;
+
+  nsXPIDLCString contractID;
+  nsresult rv = catMan->GetCategoryEntry("Gecko-Content-Viewers",
+                                         PromiseFlatCString(aType).get(),
+                                         getter_Copies(contractID));
+  if (NS_SUCCEEDED(rv)) {
+    docFactory = do_GetService(contractID);
+    if (docFactory && aLoaderType) {
+      if (contractID.EqualsLiteral(CONTENT_DLF_CONTRACTID))
+        *aLoaderType = TYPE_CONTENT;
+      else if (contractID.EqualsLiteral(PLUGIN_DLF_CONTRACTID))
+        *aLoaderType = TYPE_PLUGIN;
+      else
+      *aLoaderType = TYPE_UNKNOWN;
+    }
+    return docFactory.forget();
+  }
+
+  if (DecoderTraits::IsSupportedInVideoDocument(aType)) {
+    docFactory = do_GetService("@mozilla.org/content/document-loader-factory;1");
+    if (docFactory && aLoaderType) {
+      *aLoaderType = TYPE_CONTENT;
+    }
+    return docFactory.forget();
+  }
+
+  return nullptr;
+}
+
+static void
+ReportPatternCompileFailure(nsAString& aPattern, nsIDocument* aDocument,
+                            JSContext* cx)
+{
+    MOZ_ASSERT(JS_IsExceptionPending(cx));
+
+    JS::RootedValue exn(cx);
+    if (!JS_GetPendingException(cx, &exn)) {
+      return;
+    }
+    if (!exn.isObject()) {
+      // If pending exception is not an object, it should be OOM.
+      return;
+    }
+
+    JS::AutoSaveExceptionState savedExc(cx);
+    JS::RootedObject exnObj(cx, &exn.toObject());
+    JS::RootedValue messageVal(cx);
+    if (!JS_GetProperty(cx, exnObj, "message", &messageVal)) {
+      return;
+    }
+    MOZ_ASSERT(messageVal.isString());
+
+    JS::RootedString messageStr(cx, messageVal.toString());
+    MOZ_ASSERT(messageStr);
+
+    nsAutoString wideMessage;
+    if (!AssignJSString(cx, wideMessage, messageStr)) {
+        return;
+    }
+
+    const nsString& pattern = PromiseFlatString(aPattern);
+    const char16_t *strings[] = { pattern.get(), wideMessage.get() };
+    nsContentUtils::ReportToConsole(nsIScriptError::errorFlag,
+                                    NS_LITERAL_CSTRING("DOM"),
+                                    aDocument,
+                                    nsContentUtils::eDOM_PROPERTIES,
+                                    "PatternAttributeCompileFailure",
+                                    strings, ArrayLength(strings));
+    savedExc.drop();
+}
+
+// static
+bool
+nsContentUtils::IsPatternMatching(nsAString& aValue, nsAString& aPattern,
+                                  nsIDocument* aDocument)
+{
+  NS_ASSERTION(aDocument, "aDocument should be a valid pointer (not null)");
+
+  AutoJSAPI jsapi;
+  jsapi.Init();
+  JSContext* cx = jsapi.cx();
+
+  // We can use the junk scope here, because we're just using it for
+  // regexp evaluation, not actual script execution.
+  JSAutoCompartment ac(cx, xpc::UnprivilegedJunkScope());
+
+  // The pattern has to match the entire value.
+  aPattern.Insert(NS_LITERAL_STRING("^(?:"), 0);
+  aPattern.AppendLiteral(")$");
+
+  JS::Rooted<JSObject*> re(cx,
+    JS_NewUCRegExpObject(cx,
+                         static_cast<char16_t*>(aPattern.BeginWriting()),
+                         aPattern.Length(), JSREG_UNICODE));
+  if (!re) {
+    // Remove extra patterns added above to report with the original pattern.
+    aPattern.Cut(0, 4);
+    aPattern.Cut(aPattern.Length() - 2, 2);
+    ReportPatternCompileFailure(aPattern, aDocument, cx);
+    return true;
+  }
+
+  JS::Rooted<JS::Value> rval(cx, JS::NullValue());
+  size_t idx = 0;
+  if (!JS_ExecuteRegExpNoStatics(cx, re,
+                                 static_cast<char16_t*>(aValue.BeginWriting()),
+                                 aValue.Length(), &idx, true, &rval)) {
+    return true;
+  }
+
+  return !rval.isNull();
+}
+
+// static
+nsresult
+nsContentUtils::URIInheritsSecurityContext(nsIURI *aURI, bool *aResult)
+{
+  // Note: about:blank URIs do NOT inherit the security context from the
+  // current document, which is what this function tests for...
+  return NS_URIChainHasFlags(aURI,
+                             nsIProtocolHandler::URI_INHERITS_SECURITY_CONTEXT,
+                             aResult);
+}
+
+// static
+bool
+nsContentUtils::ChannelShouldInheritPrincipal(nsIPrincipal* aLoadingPrincipal,
+                                              nsIURI* aURI,
+                                              bool aInheritForAboutBlank,
+                                              bool aForceInherit)
+{
+  MOZ_ASSERT(aLoadingPrincipal, "Can not check inheritance without a principal");
+
+  // Only tell the channel to inherit if it can't provide its own security context.
+  //
+  // XXX: If this is ever changed, check all callers for what owners
+  //      they're passing in.  In particular, see the code and
+  //      comments in nsDocShell::LoadURI where we fall back on
+  //      inheriting the owner if called from chrome.  That would be
+  //      very wrong if this code changed anything but channels that
+  //      can't provide their own security context!
+  //
+  // If aForceInherit is true, we will inherit, even for a channel that
+  // can provide its own security context. This is used for srcdoc loads.
+  bool inherit = aForceInherit;
+  if (!inherit) {
+    bool uriInherits;
+    // We expect URIInheritsSecurityContext to return success for an
+    // about:blank URI, so don't call NS_IsAboutBlank() if this call fails.
+    // This condition needs to match the one in nsDocShell::InternalLoad where
+    // we're checking for things that will use the owner.
+    inherit =
+      (NS_SUCCEEDED(URIInheritsSecurityContext(aURI, &uriInherits)) &&
+       (uriInherits || (aInheritForAboutBlank && NS_IsAboutBlank(aURI)))) ||
+      //
+      // file: uri special-casing
+      //
+      // If this is a file: load opened from another file: then it may need
+      // to inherit the owner from the referrer so they can script each other.
+      // If we don't set the owner explicitly then each file: gets an owner
+      // based on its own codebase later.
+      //
+      (URIIsLocalFile(aURI) &&
+       NS_SUCCEEDED(aLoadingPrincipal->CheckMayLoad(aURI, false, false)) &&
+       // One more check here.  CheckMayLoad will always return true for the
+       // system principal, but we do NOT want to inherit in that case.
+       !IsSystemPrincipal(aLoadingPrincipal));
+  }
+  return inherit;
+}
+
+/* static */
+bool
+nsContentUtils::IsFullScreenApiEnabled()
+{
+  return sIsFullScreenApiEnabled;
+}
+
+/* static */
+bool
+nsContentUtils::IsRequestFullScreenAllowed()
+{
+  return !sTrustedFullScreenOnly ||
+         EventStateManager::IsHandlingUserInput() ||
+         IsCallerChrome();
+}
+
+/* static */
+bool
+nsContentUtils::IsCutCopyAllowed()
+{
+  if ((!IsCutCopyRestricted() && EventStateManager::IsHandlingUserInput()) ||
+      IsCallerChrome()) {
+    return true;
+  }
+
+  return BasePrincipal::Cast(SubjectPrincipal())->AddonHasPermission(NS_LITERAL_STRING("clipboardWrite"));
+}
+
+/* static */
+bool
+nsContentUtils::IsFrameTimingEnabled()
+{
+  return sIsFrameTimingPrefEnabled;
+}
+
+/* static */
+bool
+nsContentUtils::HaveEqualPrincipals(nsIDocument* aDoc1, nsIDocument* aDoc2)
+{
+  if (!aDoc1 || !aDoc2) {
+    return false;
+  }
+  bool principalsEqual = false;
+  aDoc1->NodePrincipal()->Equals(aDoc2->NodePrincipal(), &principalsEqual);
+  return principalsEqual;
+}
+
+/* static */
+bool
+nsContentUtils::HasPluginWithUncontrolledEventDispatch(nsIContent* aContent)
+{
+#ifdef XP_MACOSX
+  // We control dispatch to all mac plugins.
+  return false;
+#else
+  if (!aContent || !aContent->IsInUncomposedDoc()) {
+    return false;
+  }
+
+  nsCOMPtr<nsIObjectLoadingContent> olc = do_QueryInterface(aContent);
+  if (!olc) {
+    return false;
+  }
+
+  RefPtr<nsNPAPIPluginInstance> plugin;
+  olc->GetPluginInstance(getter_AddRefs(plugin));
+  if (!plugin) {
+    return false;
+  }
+
+  bool isWindowless = false;
+  nsresult res = plugin->IsWindowless(&isWindowless);
+  if (NS_FAILED(res)) {
+    return false;
+  }
+
+  return !isWindowless;
+#endif
+}
+
+/* static */
+void
+nsContentUtils::FireMutationEventsForDirectParsing(nsIDocument* aDoc,
+                                                   nsIContent* aDest,
+                                                   int32_t aOldChildCount)
+{
+  // Fire mutation events. Optimize for the case when there are no listeners
+  int32_t newChildCount = aDest->GetChildCount();
+  if (newChildCount && nsContentUtils::
+        HasMutationListeners(aDoc, NS_EVENT_BITS_MUTATION_NODEINSERTED)) {
+    AutoTArray<nsCOMPtr<nsIContent>, 50> childNodes;
+    NS_ASSERTION(newChildCount - aOldChildCount >= 0,
+                 "What, some unexpected dom mutation has happened?");
+    childNodes.SetCapacity(newChildCount - aOldChildCount);
+    for (nsIContent* child = aDest->GetFirstChild();
+         child;
+         child = child->GetNextSibling()) {
+      childNodes.AppendElement(child);
+    }
+    FragmentOrElement::FireNodeInserted(aDoc, aDest, childNodes);
+  }
+}
+
+/* static */
+nsIDocument*
+nsContentUtils::GetRootDocument(nsIDocument* aDoc)
+{
+  if (!aDoc) {
+    return nullptr;
+  }
+  nsIDocument* doc = aDoc;
+  while (doc->GetParentDocument()) {
+    doc = doc->GetParentDocument();
+  }
+  return doc;
+}
+
+/* static */
+bool
+nsContentUtils::IsInPointerLockContext(nsPIDOMWindowOuter* aWin)
+{
+  if (!aWin) {
+    return false;
+  }
+
+  nsCOMPtr<nsIDocument> pointerLockedDoc =
+    do_QueryReferent(EventStateManager::sPointerLockedDoc);
+  if (!pointerLockedDoc || !pointerLockedDoc->GetWindow()) {
+    return false;
+  }
+
+  nsCOMPtr<nsPIDOMWindowOuter> lockTop =
+    pointerLockedDoc->GetWindow()->GetScriptableTop();
+  nsCOMPtr<nsPIDOMWindowOuter> top = aWin->GetScriptableTop();
+
+  return top == lockTop;
+}
+
+// static
+int32_t
+nsContentUtils::GetAdjustedOffsetInTextControl(nsIFrame* aOffsetFrame,
+                                               int32_t aOffset)
+{
+  // The structure of the anonymous frames within a text control frame is
+  // an optional block frame, followed by an optional br frame.
+
+  // If the offset frame has a child, then this frame is the block which
+  // has the text frames (containing the content) as its children. This will
+  // be the case if we click to the right of any of the text frames, or at the
+  // bottom of the text area.
+  nsIFrame* firstChild = aOffsetFrame->PrincipalChildList().FirstChild();
+  if (firstChild) {
+    // In this case, the passed-in offset is incorrect, and we want the length
+    // of the entire content in the text control frame.
+    return firstChild->GetContent()->Length();
+  }
+
+  if (aOffsetFrame->GetPrevSibling() &&
+      !aOffsetFrame->GetNextSibling()) {
+    // In this case, we're actually within the last frame, which is a br
+    // frame. Our offset should therefore be the length of the first child of
+    // our parent.
+    int32_t aOutOffset =
+      aOffsetFrame->GetParent()->PrincipalChildList().FirstChild()->GetContent()->Length();
+    return aOutOffset;
+  }
+
+  // Otherwise, we're within one of the text frames, in which case our offset
+  // has already been correctly calculated.
+  return aOffset;
+}
+
+// static
+void
+nsContentUtils::GetSelectionInTextControl(Selection* aSelection,
+                                          Element* aRoot,
+                                          int32_t& aOutStartOffset,
+                                          int32_t& aOutEndOffset)
+{
+  MOZ_ASSERT(aSelection && aRoot);
+
+  if (!aSelection->RangeCount()) {
+    // Nothing selected
+    aOutStartOffset = aOutEndOffset = 0;
+    return;
+  }
+
+  nsCOMPtr<nsINode> anchorNode = aSelection->GetAnchorNode();
+  uint32_t anchorOffset = aSelection->AnchorOffset();
+  nsCOMPtr<nsINode> focusNode = aSelection->GetFocusNode();
+  uint32_t focusOffset = aSelection->FocusOffset();
+
+  // We have at most two children, consisting of an optional text node followed
+  // by an optional <br>.
+  NS_ASSERTION(aRoot->GetChildCount() <= 2, "Unexpected children");
+  nsCOMPtr<nsIContent> firstChild = aRoot->GetFirstChild();
+#ifdef DEBUG
+  nsCOMPtr<nsIContent> lastChild = aRoot->GetLastChild();
+  NS_ASSERTION(anchorNode == aRoot || anchorNode == firstChild ||
+               anchorNode == lastChild, "Unexpected anchorNode");
+  NS_ASSERTION(focusNode == aRoot || focusNode == firstChild ||
+               focusNode == lastChild, "Unexpected focusNode");
+#endif
+  if (!firstChild || !firstChild->IsNodeOfType(nsINode::eTEXT)) {
+    // No text node, so everything is 0
+    anchorOffset = focusOffset = 0;
+  } else {
+    // First child is text.  If the anchor/focus is already in the text node,
+    // or the start of the root node, no change needed.  If it's in the root
+    // node but not the start, or in the trailing <br>, we need to set the
+    // offset to the end.
+    if ((anchorNode == aRoot && anchorOffset != 0) ||
+        (anchorNode != aRoot && anchorNode != firstChild)) {
+      anchorOffset = firstChild->Length();
+    }
+    if ((focusNode == aRoot && focusOffset != 0) ||
+        (focusNode != aRoot && focusNode != firstChild)) {
+      focusOffset = firstChild->Length();
+    }
+  }
+
+  // Make sure aOutStartOffset <= aOutEndOffset.
+  aOutStartOffset = std::min(anchorOffset, focusOffset);
+  aOutEndOffset = std::max(anchorOffset, focusOffset);
+}
+
+
+nsIEditor*
+nsContentUtils::GetHTMLEditor(nsPresContext* aPresContext)
+{
+  nsCOMPtr<nsIDocShell> docShell(aPresContext->GetDocShell());
+  bool isEditable;
+  if (!docShell ||
+      NS_FAILED(docShell->GetEditable(&isEditable)) || !isEditable)
+    return nullptr;
+
+  nsCOMPtr<nsIEditor> editor;
+  docShell->GetEditor(getter_AddRefs(editor));
+  return editor;
+}
+
+bool
+nsContentUtils::IsContentInsertionPoint(nsIContent* aContent)
+{
+  // Check if the content is a XBL insertion point.
+  if (aContent->IsActiveChildrenElement()) {
+    return true;
+  }
+
+  // Check if the content is a web components content insertion point.
+  HTMLContentElement* contentElement =
+    HTMLContentElement::FromContent(aContent);
+  return contentElement && contentElement->IsInsertionPoint();
+}
+
+// static
+bool
+nsContentUtils::HasDistributedChildren(nsIContent* aContent)
+{
+  if (!aContent) {
+    return false;
+  }
+
+  if (aContent->GetShadowRoot()) {
+    // Children of a shadow root host are distributed
+    // to content insertion points in the shadow root.
+    return true;
+  }
+
+  ShadowRoot* shadow = ShadowRoot::FromNode(aContent);
+  if (shadow) {
+    // Children of a shadow root are distributed to
+    // the shadow insertion point of the younger shadow root.
+    return shadow->GetYoungerShadowRoot();
+  }
+
+  HTMLShadowElement* shadowEl = HTMLShadowElement::FromContent(aContent);
+  if (shadowEl && shadowEl->IsInsertionPoint()) {
+    // Children of a shadow insertion points are distributed
+    // to the insertion points in the older shadow root.
+    return shadowEl->GetOlderShadowRoot();
+  }
+
+  HTMLContentElement* contentEl = HTMLContentElement::FromContent(aContent);
+  if (contentEl && contentEl->IsInsertionPoint()) {
+    // Children of a content insertion point are distributed to the
+    // content insertion point if the content insertion point does
+    // not match any nodes (fallback content).
+    return contentEl->MatchedNodes().IsEmpty();
+  }
+
+  return false;
+}
+
+// static
+bool
+nsContentUtils::IsForbiddenRequestHeader(const nsACString& aHeader)
+{
+  if (IsForbiddenSystemRequestHeader(aHeader)) {
+    return true;
+  }
+
+  return StringBeginsWith(aHeader, NS_LITERAL_CSTRING("proxy-"),
+                          nsCaseInsensitiveCStringComparator()) ||
+         StringBeginsWith(aHeader, NS_LITERAL_CSTRING("sec-"),
+                          nsCaseInsensitiveCStringComparator());
+}
+
+// static
+bool
+nsContentUtils::IsForbiddenSystemRequestHeader(const nsACString& aHeader)
+{
+  static const char *kInvalidHeaders[] = {
+    "accept-charset", "accept-encoding", "access-control-request-headers",
+    "access-control-request-method", "connection", "content-length",
+    "cookie", "cookie2", "date", "dnt", "expect", "host", "keep-alive",
+    "origin", "referer", "te", "trailer", "transfer-encoding", "upgrade", "via"
+  };
+  for (uint32_t i = 0; i < ArrayLength(kInvalidHeaders); ++i) {
+    if (aHeader.LowerCaseEqualsASCII(kInvalidHeaders[i])) {
+      return true;
+    }
+  }
+  return false;
+}
+
+// static
+bool
+nsContentUtils::IsForbiddenResponseHeader(const nsACString& aHeader)
+{
+  return (aHeader.LowerCaseEqualsASCII("set-cookie") ||
+          aHeader.LowerCaseEqualsASCII("set-cookie2"));
+}
+
+// static
+bool
+nsContentUtils::IsAllowedNonCorsContentType(const nsACString& aHeaderValue)
+{
+  nsAutoCString contentType;
+  nsAutoCString unused;
+
+  nsresult rv = NS_ParseRequestContentType(aHeaderValue, contentType, unused);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  return contentType.LowerCaseEqualsLiteral("text/plain") ||
+         contentType.LowerCaseEqualsLiteral("application/x-www-form-urlencoded") ||
+         contentType.LowerCaseEqualsLiteral("multipart/form-data");
+}
+
+bool
+nsContentUtils::DOMWindowDumpEnabled()
+{
+#if !(defined(DEBUG) || defined(MOZ_ENABLE_JS_DUMP))
+  // In optimized builds we check a pref that controls if we should
+  // enable output from dump() or not, in debug builds it's always
+  // enabled.
+  return nsContentUtils::sDOMWindowDumpEnabled;
+#else
+  return true;
+#endif
+}
+
+bool
+nsContentUtils::DoNotTrackEnabled()
+{
+  return nsContentUtils::sDoNotTrackEnabled;
+}
+
+mozilla::LogModule*
+nsContentUtils::DOMDumpLog()
+{
+  return sDOMDumpLog;
+}
+
+bool
+nsContentUtils::GetNodeTextContent(nsINode* aNode, bool aDeep, nsAString& aResult,
+                                   const fallible_t& aFallible)
+{
+  aResult.Truncate();
+  return AppendNodeTextContent(aNode, aDeep, aResult, aFallible);
+}
+
+void
+nsContentUtils::GetNodeTextContent(nsINode* aNode, bool aDeep, nsAString& aResult)
+{
+  if (!GetNodeTextContent(aNode, aDeep, aResult, fallible)) {
+    NS_ABORT_OOM(0); // Unfortunately we don't know the allocation size
+  }
+}
+
+void
+nsContentUtils::DestroyMatchString(void* aData)
+{
+  if (aData) {
+    nsString* matchString = static_cast<nsString*>(aData);
+    delete matchString;
+  }
+}
+
+bool
+nsContentUtils::IsJavascriptMIMEType(const nsAString& aMIMEType)
+{
+  // Table ordered from most to least likely JS MIME types.
+  static const char* jsTypes[] = {
+    "text/javascript",
+    "text/ecmascript",
+    "application/javascript",
+    "application/ecmascript",
+    "application/x-javascript",
+    "application/x-ecmascript",
+    "text/javascript1.0",
+    "text/javascript1.1",
+    "text/javascript1.2",
+    "text/javascript1.3",
+    "text/javascript1.4",
+    "text/javascript1.5",
+    "text/jscript",
+    "text/livescript",
+    "text/x-ecmascript",
+    "text/x-javascript",
+    nullptr
+  };
+
+  for (uint32_t i = 0; jsTypes[i]; ++i) {
+    if (aMIMEType.LowerCaseEqualsASCII(jsTypes[i])) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+nsresult
+nsContentUtils::GenerateUUIDInPlace(nsID& aUUID)
+{
+  MOZ_ASSERT(sUUIDGenerator);
+
+  nsresult rv = sUUIDGenerator->GenerateUUIDInPlace(&aUUID);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+bool
+nsContentUtils::PrefetchEnabled(nsIDocShell* aDocShell)
+{
+  //
+  // SECURITY CHECK: disable prefetching from mailnews!
+  //
+  // walk up the docshell tree to see if any containing
+  // docshell are of type MAIL.
+  //
+
+  if (!aDocShell) {
+    return false;
+  }
+
+  nsCOMPtr<nsIDocShell> docshell = aDocShell;
+  nsCOMPtr<nsIDocShellTreeItem> parentItem;
+
+  do {
+    uint32_t appType = 0;
+    nsresult rv = docshell->GetAppType(&appType);
+    if (NS_FAILED(rv) || appType == nsIDocShell::APP_TYPE_MAIL) {
+      return false; // do not prefetch, preconnect from mailnews
+    }
+
+    docshell->GetParent(getter_AddRefs(parentItem));
+    if (parentItem) {
+      docshell = do_QueryInterface(parentItem);
+      if (!docshell) {
+        NS_ERROR("cannot get a docshell from a treeItem!");
+        return false;
+      }
+    }
+  } while (parentItem);
+
+  return true;
+}
+
+uint64_t
+nsContentUtils::GetInnerWindowID(nsIRequest* aRequest)
+{
+  // can't do anything if there's no nsIRequest!
+  if (!aRequest) {
+    return 0;
+  }
+
+  nsCOMPtr<nsILoadGroup> loadGroup;
+  nsresult rv = aRequest->GetLoadGroup(getter_AddRefs(loadGroup));
+
+  if (NS_FAILED(rv) || !loadGroup) {
+    return 0;
+  }
+
+  nsCOMPtr<nsIInterfaceRequestor> callbacks;
+  rv = loadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
+  if (NS_FAILED(rv) || !callbacks) {
+    return 0;
+  }
+
+  nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(callbacks);
+  if (!loadContext) {
+    return 0;
+  }
+
+  nsCOMPtr<mozIDOMWindowProxy> window;
+  rv = loadContext->GetAssociatedWindow(getter_AddRefs(window));
+  if (NS_FAILED(rv) || !window) {
+    return 0;
+  }
+
+  auto* pwindow = nsPIDOMWindowOuter::From(window);
+  if (!pwindow) {
+    return 0;
+  }
+
+  nsPIDOMWindowInner* inner = pwindow->GetCurrentInnerWindow();
+  return inner ? inner->WindowID() : 0;
+}
+
+nsresult
+nsContentUtils::GetHostOrIPv6WithBrackets(nsIURI* aURI, nsCString& aHost)
+{
+  aHost.Truncate();
+  nsresult rv = aURI->GetHost(aHost);
+  if (NS_FAILED(rv)) { // Some URIs do not have a host
+    return rv;
+  }
+
+  if (aHost.FindChar(':') != -1) { // Escape IPv6 address
+    MOZ_ASSERT(!aHost.Length() ||
+      (aHost[0] !='[' && aHost[aHost.Length() - 1] != ']'));
+    aHost.Insert('[', 0);
+    aHost.Append(']');
+  }
+
+  return NS_OK;
+}
+
+nsresult
+nsContentUtils::GetHostOrIPv6WithBrackets(nsIURI* aURI, nsAString& aHost)
+{
+  nsAutoCString hostname;
+  nsresult rv = GetHostOrIPv6WithBrackets(aURI, hostname);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  CopyUTF8toUTF16(hostname, aHost);
+  return NS_OK;
+}
+
+bool
+nsContentUtils::CallOnAllRemoteChildren(nsIMessageBroadcaster* aManager,
+                                        CallOnRemoteChildFunction aCallback,
+                                        void* aArg)
+{
+  uint32_t tabChildCount = 0;
+  aManager->GetChildCount(&tabChildCount);
+  for (uint32_t j = 0; j < tabChildCount; ++j) {
+    nsCOMPtr<nsIMessageListenerManager> childMM;
+    aManager->GetChildAt(j, getter_AddRefs(childMM));
+    if (!childMM) {
+      continue;
+    }
+
+    nsCOMPtr<nsIMessageBroadcaster> nonLeafMM = do_QueryInterface(childMM);
+    if (nonLeafMM) {
+      if (CallOnAllRemoteChildren(nonLeafMM, aCallback, aArg)) {
+        return true;
+      }
+      continue;
+    }
+
+    nsCOMPtr<nsIMessageSender> tabMM = do_QueryInterface(childMM);
+
+    mozilla::dom::ipc::MessageManagerCallback* cb =
+     static_cast<nsFrameMessageManager*>(tabMM.get())->GetCallback();
+    if (cb) {
+      nsFrameLoader* fl = static_cast<nsFrameLoader*>(cb);
+      TabParent* remote = TabParent::GetFrom(fl);
+      if (remote && aCallback) {
+        if (aCallback(remote, aArg)) {
+          return true;
+        }
+      }
+    }
+  }
+
+  return false;
+}
+
+void
+nsContentUtils::CallOnAllRemoteChildren(nsPIDOMWindowOuter* aWindow,
+                                        CallOnRemoteChildFunction aCallback,
+                                        void* aArg)
+{
+  nsCOMPtr<nsIDOMChromeWindow> chromeWindow(do_QueryInterface(aWindow));
+  if (chromeWindow) {
+    nsCOMPtr<nsIMessageBroadcaster> windowMM;
+    chromeWindow->GetMessageManager(getter_AddRefs(windowMM));
+    if (windowMM) {
+      CallOnAllRemoteChildren(windowMM, aCallback, aArg);
+    }
+  }
+}
+
+struct UIStateChangeInfo {
+  UIStateChangeType mShowAccelerators;
+  UIStateChangeType mShowFocusRings;
+
+  UIStateChangeInfo(UIStateChangeType aShowAccelerators,
+                    UIStateChangeType aShowFocusRings)
+    : mShowAccelerators(aShowAccelerators),
+      mShowFocusRings(aShowFocusRings)
+  {}
+};
+
+bool
+SetKeyboardIndicatorsChild(TabParent* aParent, void* aArg)
+{
+  UIStateChangeInfo* stateInfo = static_cast<UIStateChangeInfo*>(aArg);
+  Unused << aParent->SendSetKeyboardIndicators(stateInfo->mShowAccelerators,
+                                               stateInfo->mShowFocusRings);
+  return false;
+}
+
+void
+nsContentUtils::SetKeyboardIndicatorsOnRemoteChildren(nsPIDOMWindowOuter* aWindow,
+                                                      UIStateChangeType aShowAccelerators,
+                                                      UIStateChangeType aShowFocusRings)
+{
+  UIStateChangeInfo stateInfo(aShowAccelerators, aShowFocusRings);
+  CallOnAllRemoteChildren(aWindow, SetKeyboardIndicatorsChild,
+                          (void *)&stateInfo);
+}
+
+nsresult
+nsContentUtils::IPCTransferableToTransferable(const IPCDataTransfer& aDataTransfer,
+                                              const bool& aIsPrivateData,
+                                              nsIPrincipal* aRequestingPrincipal,
+                                              nsITransferable* aTransferable,
+                                              mozilla::dom::nsIContentParent* aContentParent,
+                                              mozilla::dom::TabChild* aTabChild)
+{
+  nsresult rv;
+
+  const nsTArray<IPCDataTransferItem>& items = aDataTransfer.items();
+  for (const auto& item : items) {
+    aTransferable->AddDataFlavor(item.flavor().get());
+
+    if (item.data().type() == IPCDataTransferData::TnsString) {
+      nsCOMPtr<nsISupportsString> dataWrapper =
+        do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID, &rv);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      const nsString& text = item.data().get_nsString();
+      rv = dataWrapper->SetData(text);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      rv = aTransferable->SetTransferData(item.flavor().get(), dataWrapper,
+                                  text.Length() * sizeof(char16_t));
+
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else if (item.data().type() == IPCDataTransferData::TShmem) {
+      if (nsContentUtils::IsFlavorImage(item.flavor())) {
+        nsCOMPtr<imgIContainer> imageContainer;
+        rv = nsContentUtils::DataTransferItemToImage(item,
+                                                     getter_AddRefs(imageContainer));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        nsCOMPtr<nsISupportsInterfacePointer> imgPtr =
+          do_CreateInstance(NS_SUPPORTS_INTERFACE_POINTER_CONTRACTID);
+        NS_ENSURE_TRUE(imgPtr, NS_ERROR_FAILURE);
+
+        rv = imgPtr->SetData(imageContainer);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        aTransferable->SetTransferData(item.flavor().get(), imgPtr, sizeof(nsISupports*));
+      } else {
+        nsCOMPtr<nsISupportsCString> dataWrapper =
+          do_CreateInstance(NS_SUPPORTS_CSTRING_CONTRACTID, &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        // The buffer contains the terminating null.
+        Shmem itemData = item.data().get_Shmem();
+        const nsDependentCString text(itemData.get<char>(),
+                                      itemData.Size<char>());
+        rv = dataWrapper->SetData(text);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        rv = aTransferable->SetTransferData(item.flavor().get(), dataWrapper, text.Length());
+
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+
+      if (aContentParent) {
+        Unused << aContentParent->DeallocShmem(item.data().get_Shmem());
+      } else if (aTabChild) {
+        Unused << aTabChild->DeallocShmem(item.data().get_Shmem());
+      }
+    }
+  }
+
+  aTransferable->SetIsPrivateData(aIsPrivateData);
+  aTransferable->SetRequestingPrincipal(aRequestingPrincipal);
+  return NS_OK;
+}
+
+void
+nsContentUtils::TransferablesToIPCTransferables(nsIArray* aTransferables,
+                                                nsTArray<IPCDataTransfer>& aIPC,
+                                                bool aInSyncMessage,
+                                                mozilla::dom::nsIContentChild* aChild,
+                                                mozilla::dom::nsIContentParent* aParent)
+{
+  aIPC.Clear();
+  if (aTransferables) {
+    uint32_t transferableCount = 0;
+    aTransferables->GetLength(&transferableCount);
+    for (uint32_t i = 0; i < transferableCount; ++i) {
+      IPCDataTransfer* dt = aIPC.AppendElement();
+      nsCOMPtr<nsITransferable> transferable = do_QueryElementAt(aTransferables, i);
+      TransferableToIPCTransferable(transferable, dt, aInSyncMessage, aChild, aParent);
+    }
+  }
+}
+
+nsresult
+nsContentUtils::SlurpFileToString(nsIFile* aFile, nsACString& aString)
+{
+  aString.Truncate();
+
+  nsCOMPtr<nsIURI> fileURI;
+  nsresult rv = NS_NewFileURI(getter_AddRefs(fileURI), aFile);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIChannel> channel;
+  rv = NS_NewChannel(getter_AddRefs(channel),
+                     fileURI,
+                     nsContentUtils::GetSystemPrincipal(),
+                     nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
+                     nsIContentPolicy::TYPE_OTHER);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIInputStream> stream;
+  rv = channel->Open2(getter_AddRefs(stream));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = NS_ConsumeStream(stream, UINT32_MAX, aString);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = stream->Close();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+bool
+nsContentUtils::IsFileImage(nsIFile* aFile, nsACString& aType)
+{
+  nsCOMPtr<nsIMIMEService> mime = do_GetService("@mozilla.org/mime;1");
+  if (!mime) {
+    return false;
+  }
+
+  nsresult rv = mime->GetTypeFromFile(aFile, aType);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  return StringBeginsWith(aType, NS_LITERAL_CSTRING("image/"));
+}
+
+nsresult
+nsContentUtils::DataTransferItemToImage(const IPCDataTransferItem& aItem,
+                                        imgIContainer** aContainer)
+{
+  MOZ_ASSERT(aItem.data().type() == IPCDataTransferData::TShmem);
+  MOZ_ASSERT(IsFlavorImage(aItem.flavor()));
+
+  const IPCDataTransferImage& imageDetails = aItem.imageDetails();
+  const IntSize size(imageDetails.width(), imageDetails.height());
+  if (!size.width || !size.height) {
+    return NS_ERROR_FAILURE;
+  }
+
+  Shmem data = aItem.data().get_Shmem();
+
+  RefPtr<DataSourceSurface> image =
+      CreateDataSourceSurfaceFromData(size,
+                                      static_cast<SurfaceFormat>(imageDetails.format()),
+                                      data.get<uint8_t>(),
+                                      imageDetails.stride());
+
+  RefPtr<gfxDrawable> drawable = new gfxSurfaceDrawable(image, size);
+  nsCOMPtr<imgIContainer> imageContainer =
+    image::ImageOps::CreateFromDrawable(drawable);
+  imageContainer.forget(aContainer);
+
+  return NS_OK;
+}
+
+bool
+nsContentUtils::IsFlavorImage(const nsACString& aFlavor)
+{
+  return aFlavor.EqualsLiteral(kNativeImageMime) ||
+         aFlavor.EqualsLiteral(kJPEGImageMime) ||
+         aFlavor.EqualsLiteral(kJPGImageMime) ||
+         aFlavor.EqualsLiteral(kPNGImageMime) ||
+         aFlavor.EqualsLiteral(kGIFImageMime);
+}
+
+static Shmem
+ConvertToShmem(mozilla::dom::nsIContentChild* aChild,
+               mozilla::dom::nsIContentParent* aParent,
+               const nsACString& aInput)
+{
+  MOZ_ASSERT((aChild && !aParent) || (!aChild && aParent));
+
+  IShmemAllocator* allocator =
+    aChild ? static_cast<IShmemAllocator*>(aChild)
+           : static_cast<IShmemAllocator*>(aParent);
+
+  Shmem result;
+  if (!allocator->AllocShmem(aInput.Length() + 1,
+                             SharedMemory::TYPE_BASIC,
+                             &result)) {
+    return result;
+  }
+
+  memcpy(result.get<char>(),
+         aInput.BeginReading(),
+         aInput.Length() + 1);
+
+  return result;
+}
+
+void
+nsContentUtils::TransferableToIPCTransferable(nsITransferable* aTransferable,
+                                              IPCDataTransfer* aIPCDataTransfer,
+                                              bool aInSyncMessage,
+                                              mozilla::dom::nsIContentChild* aChild,
+                                              mozilla::dom::nsIContentParent* aParent)
+{
+  MOZ_ASSERT((aChild && !aParent) || (!aChild && aParent));
+
+  if (aTransferable) {
+    nsCOMPtr<nsIArray> flavorList;
+    aTransferable->FlavorsTransferableCanExport(getter_AddRefs(flavorList));
+    if (flavorList) {
+      uint32_t flavorCount = 0;
+      flavorList->GetLength(&flavorCount);
+      for (uint32_t j = 0; j < flavorCount; ++j) {
+        nsCOMPtr<nsISupportsCString> flavor = do_QueryElementAt(flavorList, j);
+        if (!flavor) {
+          continue;
+        }
+
+        nsAutoCString flavorStr;
+        flavor->GetData(flavorStr);
+        if (!flavorStr.Length()) {
+          continue;
+        }
+
+        nsCOMPtr<nsISupports> data;
+        uint32_t dataLen = 0;
+        aTransferable->GetTransferData(flavorStr.get(), getter_AddRefs(data), &dataLen);
+
+        nsCOMPtr<nsISupportsString> text = do_QueryInterface(data);
+        nsCOMPtr<nsISupportsCString> ctext = do_QueryInterface(data);
+        if (text) {
+          nsAutoString dataAsString;
+          text->GetData(dataAsString);
+          IPCDataTransferItem* item = aIPCDataTransfer->items().AppendElement();
+          item->flavor() = flavorStr;
+          item->data() = dataAsString;
+        } else if (ctext) {
+          nsAutoCString dataAsString;
+          ctext->GetData(dataAsString);
+          IPCDataTransferItem* item = aIPCDataTransfer->items().AppendElement();
+          item->flavor() = flavorStr;
+
+          Shmem dataAsShmem = ConvertToShmem(aChild, aParent, dataAsString);
+          if (!dataAsShmem.IsReadable() || !dataAsShmem.Size<char>()) {
+            continue;
+          }
+
+          item->data() = dataAsShmem;
+        } else {
+          nsCOMPtr<nsISupportsInterfacePointer> sip =
+            do_QueryInterface(data);
+          if (sip) {
+            sip->GetData(getter_AddRefs(data));
+          }
+
+          // Images to be pasted on the clipboard are nsIInputStreams
+          nsCOMPtr<nsIInputStream> stream(do_QueryInterface(data));
+          if (stream) {
+            IPCDataTransferItem* item = aIPCDataTransfer->items().AppendElement();
+            item->flavor() = flavorStr;
+
+            nsCString imageData;
+            NS_ConsumeStream(stream, UINT32_MAX, imageData);
+
+            Shmem imageDataShmem = ConvertToShmem(aChild, aParent, imageData);
+            if (!imageDataShmem.IsReadable() || !imageDataShmem.Size<char>()) {
+              continue;
+            }
+
+            item->data() = imageDataShmem;
+            continue;
+          }
+
+          // Images to be placed on the clipboard are imgIContainers.
+          nsCOMPtr<imgIContainer> image(do_QueryInterface(data));
+          if (image) {
+            RefPtr<mozilla::gfx::SourceSurface> surface =
+              image->GetFrame(imgIContainer::FRAME_CURRENT,
+                              imgIContainer::FLAG_SYNC_DECODE);
+            if (!surface) {
+              continue;
+            }
+            RefPtr<mozilla::gfx::DataSourceSurface> dataSurface =
+              surface->GetDataSurface();
+            if (!dataSurface) {
+              continue;
+            }
+            size_t length;
+            int32_t stride;
+            Shmem surfaceData;
+            IShmemAllocator* allocator = aChild ? static_cast<IShmemAllocator*>(aChild)
+                                                : static_cast<IShmemAllocator*>(aParent);
+            GetSurfaceData(dataSurface, &length, &stride,
+                           allocator,
+                           &surfaceData);
+
+            IPCDataTransferItem* item = aIPCDataTransfer->items().AppendElement();
+            item->flavor() = flavorStr;
+            // Turn item->data() into an nsCString prior to accessing it.
+            item->data() = surfaceData;
+
+            IPCDataTransferImage& imageDetails = item->imageDetails();
+            mozilla::gfx::IntSize size = dataSurface->GetSize();
+            imageDetails.width() = size.width;
+            imageDetails.height() = size.height;
+            imageDetails.stride() = stride;
+            imageDetails.format() = static_cast<uint8_t>(dataSurface->GetFormat());
+
+            continue;
+          }
+
+          // Otherwise, handle this as a file.
+          nsCOMPtr<BlobImpl> blobImpl;
+          nsCOMPtr<nsIFile> file = do_QueryInterface(data);
+          if (file) {
+            // If we can send this over as a blob, do so. Otherwise, we're
+            // responding to a sync message and the child can't process the blob
+            // constructor before processing our response, which would crash. In
+            // that case, hope that the caller is nsClipboardProxy::GetData,
+            // called from editor and send over images as raw data.
+            if (aInSyncMessage) {
+              nsAutoCString type;
+              if (IsFileImage(file, type)) {
+                IPCDataTransferItem* item = aIPCDataTransfer->items().AppendElement();
+                item->flavor() = type;
+                nsAutoCString data;
+                SlurpFileToString(file, data);
+
+                Shmem dataAsShmem = ConvertToShmem(aChild, aParent, data);
+                item->data() = dataAsShmem;
+              }
+
+              continue;
+            }
+
+            if (aParent) {
+              bool isDir = false;
+              if (NS_SUCCEEDED(file->IsDirectory(&isDir)) && isDir) {
+                nsAutoString path;
+                if (NS_WARN_IF(NS_FAILED(file->GetPath(path)))) {
+                  continue;
+                }
+
+                RefPtr<FileSystemSecurity> fss = FileSystemSecurity::GetOrCreate();
+                fss->GrantAccessToContentProcess(aParent->ChildID(), path);
+              }
+            }
+
+            blobImpl = new BlobImplFile(file, false);
+            ErrorResult rv;
+            // Ensure that file data is cached no that the content process
+            // has this data available to it when passed over:
+            blobImpl->GetSize(rv);
+            blobImpl->GetLastModified(rv);
+          } else {
+            if (aInSyncMessage) {
+              // Can't do anything.
+              continue;
+            }
+            blobImpl = do_QueryInterface(data);
+          }
+          if (blobImpl) {
+            IPCDataTransferData data;
+
+            // If we failed to create the blob actor, then this blob probably
+            // can't get the file size for the underlying file, ignore it for
+            // now. TODO pass this through anyway.
+            if (aChild) {
+              auto* child = mozilla::dom::BlobChild::GetOrCreate(aChild,
+                              static_cast<BlobImpl*>(blobImpl.get()));
+              if (!child) {
+                continue;
+              }
+
+              data = child;
+            } else if (aParent) {
+              auto* parent = mozilla::dom::BlobParent::GetOrCreate(aParent,
+                               static_cast<BlobImpl*>(blobImpl.get()));
+              if (!parent) {
+                continue;
+              }
+
+              data = parent;
+            }
+
+            IPCDataTransferItem* item = aIPCDataTransfer->items().AppendElement();
+            item->flavor() = flavorStr;
+            item->data() = data;
+          } else {
+            // This is a hack to support kFilePromiseMime.
+            // On Windows there just needs to be an entry for it,
+            // and for OSX we need to create
+            // nsContentAreaDragDropDataProvider as nsIFlavorDataProvider.
+            if (flavorStr.EqualsLiteral(kFilePromiseMime)) {
+              IPCDataTransferItem* item = aIPCDataTransfer->items().AppendElement();
+              item->flavor() = flavorStr;
+              item->data() = NS_ConvertUTF8toUTF16(flavorStr);
+            } else if (!data) {
+              // Empty element, transfer only the flavor
+              IPCDataTransferItem* item = aIPCDataTransfer->items().AppendElement();
+              item->flavor() = flavorStr;
+              item->data() = nsString();
+              continue;
+            }
+          }
+        }
+      }
+    }
+  }
+}
+
+namespace {
+// The default type used for calling GetSurfaceData(). Gets surface data as
+// raw buffer.
+struct GetSurfaceDataRawBuffer
+{
+  using ReturnType = mozilla::UniquePtr<char[]>;
+  using BufferType = char*;
+
+  ReturnType Allocate(size_t aSize)
+  {
+    return ReturnType(new char[aSize]);
+  }
+
+  static BufferType
+  GetBuffer(const ReturnType& aReturnValue)
+  {
+    return aReturnValue.get();
+  }
+
+  static ReturnType
+  NullValue()
+  {
+    return ReturnType();
+  }
+};
+
+// The type used for calling GetSurfaceData() that allocates and writes to
+// a shared memory buffer.
+struct GetSurfaceDataShmem
+{
+  using ReturnType = Shmem;
+  using BufferType = char*;
+
+  explicit GetSurfaceDataShmem(IShmemAllocator* aAllocator)
+    : mAllocator(aAllocator)
+  { }
+
+  ReturnType Allocate(size_t aSize)
+  {
+    Shmem returnValue;
+    mAllocator->AllocShmem(aSize,
+                           SharedMemory::TYPE_BASIC,
+                           &returnValue);
+    return returnValue;
+  }
+
+  static BufferType
+  GetBuffer(ReturnType aReturnValue)
+  {
+    return aReturnValue.get<char>();
+  }
+
+  static ReturnType
+  NullValue()
+  {
+    return ReturnType();
+  }
+private:
+  IShmemAllocator* mAllocator;
+};
+
+/*
+ * Get the pixel data from the given source surface and return it as a buffer.
+ * The length and stride will be assigned from the surface.
+ */
+template <typename GetSurfaceDataContext = GetSurfaceDataRawBuffer>
+typename GetSurfaceDataContext::ReturnType
+GetSurfaceDataImpl(mozilla::gfx::DataSourceSurface* aSurface,
+                   size_t* aLength, int32_t* aStride,
+                   GetSurfaceDataContext aContext = GetSurfaceDataContext())
+{
+  mozilla::gfx::DataSourceSurface::MappedSurface map;
+  if (!aSurface->Map(mozilla::gfx::DataSourceSurface::MapType::READ, &map)) {
+    return GetSurfaceDataContext::NullValue();
+  }
+
+  mozilla::gfx::IntSize size = aSurface->GetSize();
+  mozilla::CheckedInt32 requiredBytes =
+    mozilla::CheckedInt32(map.mStride) * mozilla::CheckedInt32(size.height);
+  if (!requiredBytes.isValid()) {
+    return GetSurfaceDataContext::NullValue();
+  }
+
+  size_t maxBufLen = requiredBytes.value();
+  mozilla::gfx::SurfaceFormat format = aSurface->GetFormat();
+
+  // Surface data handling is totally nuts. This is the magic one needs to
+  // know to access the data.
+  size_t bufLen = maxBufLen - map.mStride + (size.width * BytesPerPixel(format));
+
+  // nsDependentCString wants null-terminated string.
+  typename GetSurfaceDataContext::ReturnType surfaceData = aContext.Allocate(maxBufLen + 1);
+  if (GetSurfaceDataContext::GetBuffer(surfaceData)) {
+    memcpy(GetSurfaceDataContext::GetBuffer(surfaceData),
+           reinterpret_cast<char*>(map.mData),
+           bufLen);
+    memset(GetSurfaceDataContext::GetBuffer(surfaceData) + bufLen,
+           0,
+           maxBufLen - bufLen + 1);
+  }
+
+  *aLength = maxBufLen;
+  *aStride = map.mStride;
+
+  aSurface->Unmap();
+  return surfaceData;
+}
+} // Anonymous namespace.
+
+mozilla::UniquePtr<char[]>
+nsContentUtils::GetSurfaceData(
+  NotNull<mozilla::gfx::DataSourceSurface*> aSurface,
+  size_t* aLength, int32_t* aStride)
+{
+  return GetSurfaceDataImpl(aSurface, aLength, aStride);
+}
+
+void
+nsContentUtils::GetSurfaceData(mozilla::gfx::DataSourceSurface* aSurface,
+                               size_t* aLength, int32_t* aStride,
+                               IShmemAllocator* aAllocator,
+                               Shmem *aOutShmem)
+{
+  *aOutShmem = GetSurfaceDataImpl(aSurface, aLength, aStride,
+                                  GetSurfaceDataShmem(aAllocator));
+}
+
+mozilla::Modifiers
+nsContentUtils::GetWidgetModifiers(int32_t aModifiers)
+{
+  Modifiers result = 0;
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_SHIFT) {
+    result |= mozilla::MODIFIER_SHIFT;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_CONTROL) {
+    result |= mozilla::MODIFIER_CONTROL;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_ALT) {
+    result |= mozilla::MODIFIER_ALT;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_META) {
+    result |= mozilla::MODIFIER_META;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_ALTGRAPH) {
+    result |= mozilla::MODIFIER_ALTGRAPH;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_CAPSLOCK) {
+    result |= mozilla::MODIFIER_CAPSLOCK;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_FN) {
+    result |= mozilla::MODIFIER_FN;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_FNLOCK) {
+    result |= mozilla::MODIFIER_FNLOCK;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_NUMLOCK) {
+    result |= mozilla::MODIFIER_NUMLOCK;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_SCROLLLOCK) {
+    result |= mozilla::MODIFIER_SCROLLLOCK;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_SYMBOL) {
+    result |= mozilla::MODIFIER_SYMBOL;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_SYMBOLLOCK) {
+    result |= mozilla::MODIFIER_SYMBOLLOCK;
+  }
+  if (aModifiers & nsIDOMWindowUtils::MODIFIER_OS) {
+    result |= mozilla::MODIFIER_OS;
+  }
+  return result;
+}
+
+nsIWidget*
+nsContentUtils::GetWidget(nsIPresShell* aPresShell, nsPoint* aOffset) {
+  if (aPresShell) {
+    nsIFrame* frame = aPresShell->GetRootFrame();
+    if (frame)
+      return frame->GetView()->GetNearestWidget(aOffset);
+  }
+  return nullptr;
+}
+
+int16_t
+nsContentUtils::GetButtonsFlagForButton(int32_t aButton)
+{
+  switch (aButton) {
+    case -1:
+      return WidgetMouseEvent::eNoButtonFlag;
+    case WidgetMouseEvent::eLeftButton:
+      return WidgetMouseEvent::eLeftButtonFlag;
+    case WidgetMouseEvent::eMiddleButton:
+      return WidgetMouseEvent::eMiddleButtonFlag;
+    case WidgetMouseEvent::eRightButton:
+      return WidgetMouseEvent::eRightButtonFlag;
+    case 4:
+      return WidgetMouseEvent::e4thButtonFlag;
+    case 5:
+      return WidgetMouseEvent::e5thButtonFlag;
+    default:
+      NS_ERROR("Button not known.");
+      return 0;
+  }
+}
+
+LayoutDeviceIntPoint
+nsContentUtils::ToWidgetPoint(const CSSPoint& aPoint,
+                              const nsPoint& aOffset,
+                              nsPresContext* aPresContext)
+{
+  return LayoutDeviceIntPoint::FromAppUnitsRounded(
+    (CSSPoint::ToAppUnits(aPoint) +
+    aOffset).ApplyResolution(nsLayoutUtils::GetCurrentAPZResolutionScale(aPresContext->PresShell())),
+    aPresContext->AppUnitsPerDevPixel());
+}
+
+nsView*
+nsContentUtils::GetViewToDispatchEvent(nsPresContext* presContext,
+                                       nsIPresShell** presShell)
+{
+  if (presContext && presShell) {
+    *presShell = presContext->PresShell();
+    if (*presShell) {
+      NS_ADDREF(*presShell);
+      if (nsViewManager* viewManager = (*presShell)->GetViewManager()) {
+        if (nsView* view = viewManager->GetRootView()) {
+          return view;
+        }
+      }
+    }
+  }
+  return nullptr;
+}
+
+nsresult
+nsContentUtils::SendKeyEvent(nsIWidget* aWidget,
+                             const nsAString& aType,
+                             int32_t aKeyCode,
+                             int32_t aCharCode,
+                             int32_t aModifiers,
+                             uint32_t aAdditionalFlags,
+                             bool* aDefaultActionTaken)
+{
+  // get the widget to send the event to
+  if (!aWidget)
+    return NS_ERROR_FAILURE;
+
+  EventMessage msg;
+  if (aType.EqualsLiteral("keydown"))
+    msg = eKeyDown;
+  else if (aType.EqualsLiteral("keyup"))
+    msg = eKeyUp;
+  else if (aType.EqualsLiteral("keypress"))
+    msg = eKeyPress;
+  else
+    return NS_ERROR_FAILURE;
+
+  WidgetKeyboardEvent event(true, msg, aWidget);
+  event.mModifiers = GetWidgetModifiers(aModifiers);
+
+  if (msg == eKeyPress) {
+    event.mKeyCode = aCharCode ? 0 : aKeyCode;
+    event.mCharCode = aCharCode;
+  } else {
+    event.mKeyCode = aKeyCode;
+    event.mCharCode = 0;
+  }
+
+  uint32_t locationFlag = (aAdditionalFlags &
+    (nsIDOMWindowUtils::KEY_FLAG_LOCATION_STANDARD | nsIDOMWindowUtils::KEY_FLAG_LOCATION_LEFT |
+     nsIDOMWindowUtils::KEY_FLAG_LOCATION_RIGHT | nsIDOMWindowUtils::KEY_FLAG_LOCATION_NUMPAD));
+  switch (locationFlag) {
+    case nsIDOMWindowUtils::KEY_FLAG_LOCATION_STANDARD:
+      event.mLocation = nsIDOMKeyEvent::DOM_KEY_LOCATION_STANDARD;
+      break;
+    case nsIDOMWindowUtils::KEY_FLAG_LOCATION_LEFT:
+      event.mLocation = nsIDOMKeyEvent::DOM_KEY_LOCATION_LEFT;
+      break;
+    case nsIDOMWindowUtils::KEY_FLAG_LOCATION_RIGHT:
+      event.mLocation = nsIDOMKeyEvent::DOM_KEY_LOCATION_RIGHT;
+      break;
+    case nsIDOMWindowUtils::KEY_FLAG_LOCATION_NUMPAD:
+      event.mLocation = nsIDOMKeyEvent::DOM_KEY_LOCATION_NUMPAD;
+      break;
+    default:
+      if (locationFlag != 0) {
+        return NS_ERROR_INVALID_ARG;
+      }
+      // If location flag isn't set, choose the location from keycode.
+      switch (aKeyCode) {
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD0:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD1:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD2:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD3:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD4:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD5:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD6:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD7:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD8:
+        case nsIDOMKeyEvent::DOM_VK_NUMPAD9:
+        case nsIDOMKeyEvent::DOM_VK_MULTIPLY:
+        case nsIDOMKeyEvent::DOM_VK_ADD:
+        case nsIDOMKeyEvent::DOM_VK_SEPARATOR:
+        case nsIDOMKeyEvent::DOM_VK_SUBTRACT:
+        case nsIDOMKeyEvent::DOM_VK_DECIMAL:
+        case nsIDOMKeyEvent::DOM_VK_DIVIDE:
+          event.mLocation = nsIDOMKeyEvent::DOM_KEY_LOCATION_NUMPAD;
+          break;
+        case nsIDOMKeyEvent::DOM_VK_SHIFT:
+        case nsIDOMKeyEvent::DOM_VK_CONTROL:
+        case nsIDOMKeyEvent::DOM_VK_ALT:
+        case nsIDOMKeyEvent::DOM_VK_META:
+          event.mLocation = nsIDOMKeyEvent::DOM_KEY_LOCATION_LEFT;
+          break;
+        default:
+          event.mLocation = nsIDOMKeyEvent::DOM_KEY_LOCATION_STANDARD;
+          break;
+      }
+      break;
+  }
+
+  event.mRefPoint = LayoutDeviceIntPoint(0, 0);
+  event.mTime = PR_IntervalNow();
+  if (!(aAdditionalFlags & nsIDOMWindowUtils::KEY_FLAG_NOT_SYNTHESIZED_FOR_TESTS)) {
+    event.mFlags.mIsSynthesizedForTests = true;
+  }
+
+  if (aAdditionalFlags & nsIDOMWindowUtils::KEY_FLAG_PREVENT_DEFAULT) {
+    event.PreventDefaultBeforeDispatch();
+  }
+
+  nsEventStatus status;
+  nsresult rv = aWidget->DispatchEvent(&event, status);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *aDefaultActionTaken = (status != nsEventStatus_eConsumeNoDefault);
+
+  return NS_OK;
+}
+
+nsresult
+nsContentUtils::SendMouseEvent(nsCOMPtr<nsIPresShell> aPresShell,
+                               const nsAString& aType,
+                               float aX,
+                               float aY,
+                               int32_t aButton,
+                               int32_t aButtons,
+                               int32_t aClickCount,
+                               int32_t aModifiers,
+                               bool aIgnoreRootScrollFrame,
+                               float aPressure,
+                               unsigned short aInputSourceArg,
+                               bool aToWindow,
+                               bool *aPreventDefault,
+                               bool aIsDOMEventSynthesized,
+                               bool aIsWidgetEventSynthesized)
+{
+  nsPoint offset;
+  nsCOMPtr<nsIWidget> widget = GetWidget(aPresShell, &offset);
+  if (!widget)
+    return NS_ERROR_FAILURE;
+
+  EventMessage msg;
+  WidgetMouseEvent::ExitFrom exitFrom = WidgetMouseEvent::eChild;
+  bool contextMenuKey = false;
+  if (aType.EqualsLiteral("mousedown")) {
+    msg = eMouseDown;
+  } else if (aType.EqualsLiteral("mouseup")) {
+    msg = eMouseUp;
+  } else if (aType.EqualsLiteral("mousemove")) {
+    msg = eMouseMove;
+  } else if (aType.EqualsLiteral("mouseover")) {
+    msg = eMouseEnterIntoWidget;
+  } else if (aType.EqualsLiteral("mouseout")) {
+    msg = eMouseExitFromWidget;
+  } else if (aType.EqualsLiteral("mousecancel")) {
+    msg = eMouseExitFromWidget;
+    exitFrom = WidgetMouseEvent::eTopLevel;
+  } else if (aType.EqualsLiteral("mouselongtap")) {
+    msg = eMouseLongTap;
+  } else if (aType.EqualsLiteral("contextmenu")) {
+    msg = eContextMenu;
+    contextMenuKey = (aButton == 0);
+  } else if (aType.EqualsLiteral("MozMouseHittest")) {
+    msg = eMouseHitTest;
+  } else {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (aInputSourceArg == nsIDOMMouseEvent::MOZ_SOURCE_UNKNOWN) {
+    aInputSourceArg = nsIDOMMouseEvent::MOZ_SOURCE_MOUSE;
+  }
+
+  WidgetMouseEvent event(true, msg, widget,
+                         aIsWidgetEventSynthesized ?
+                           WidgetMouseEvent::eSynthesized :
+                           WidgetMouseEvent::eReal,
+                         contextMenuKey ? WidgetMouseEvent::eContextMenuKey :
+                                          WidgetMouseEvent::eNormal);
+  event.mModifiers = GetWidgetModifiers(aModifiers);
+  event.button = aButton;
+  event.buttons = aButtons != nsIDOMWindowUtils::MOUSE_BUTTONS_NOT_SPECIFIED ?
+                  aButtons :
+                  msg == eMouseUp ? 0 : GetButtonsFlagForButton(aButton);
+  event.pressure = aPressure;
+  event.inputSource = aInputSourceArg;
+  event.mClickCount = aClickCount;
+  event.mTime = PR_IntervalNow();
+  event.mFlags.mIsSynthesizedForTests = aIsDOMEventSynthesized;
+  event.mExitFrom = exitFrom;
+
+  nsPresContext* presContext = aPresShell->GetPresContext();
+  if (!presContext)
+    return NS_ERROR_FAILURE;
+
+  event.mRefPoint = ToWidgetPoint(CSSPoint(aX, aY), offset, presContext);
+  event.mIgnoreRootScrollFrame = aIgnoreRootScrollFrame;
+
+  nsEventStatus status = nsEventStatus_eIgnore;
+  if (aToWindow) {
+    nsCOMPtr<nsIPresShell> presShell;
+    nsView* view = GetViewToDispatchEvent(presContext, getter_AddRefs(presShell));
+    if (!presShell || !view) {
+      return NS_ERROR_FAILURE;
+    }
+    return presShell->HandleEvent(view->GetFrame(), &event, false, &status);
+  }
+  if (gfxPrefs::TestEventsAsyncEnabled()) {
+    status = widget->DispatchInputEvent(&event);
+  } else {
+    nsresult rv = widget->DispatchEvent(&event, status);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  if (aPreventDefault) {
+    *aPreventDefault = (status == nsEventStatus_eConsumeNoDefault);
+  }
+
+  return NS_OK;
+}
+
+/* static */
+void
+nsContentUtils::FirePageHideEvent(nsIDocShellTreeItem* aItem,
+                                  EventTarget* aChromeEventHandler)
+{
+  nsCOMPtr<nsIDocument> doc = aItem->GetDocument();
+  NS_ASSERTION(doc, "What happened here?");
+  doc->OnPageHide(true, aChromeEventHandler);
+
+  int32_t childCount = 0;
+  aItem->GetChildCount(&childCount);
+  AutoTArray<nsCOMPtr<nsIDocShellTreeItem>, 8> kids;
+  kids.AppendElements(childCount);
+  for (int32_t i = 0; i < childCount; ++i) {
+    aItem->GetChildAt(i, getter_AddRefs(kids[i]));
+  }
+
+  for (uint32_t i = 0; i < kids.Length(); ++i) {
+    if (kids[i]) {
+      FirePageHideEvent(kids[i], aChromeEventHandler);
+    }
+  }
+}
+
+// The pageshow event is fired for a given document only if IsShowing() returns
+// the same thing as aFireIfShowing.  This gives us a way to fire pageshow only
+// on documents that are still loading or only on documents that are already
+// loaded.
+/* static */
+void
+nsContentUtils::FirePageShowEvent(nsIDocShellTreeItem* aItem,
+                                  EventTarget* aChromeEventHandler,
+                                  bool aFireIfShowing)
+{
+  int32_t childCount = 0;
+  aItem->GetChildCount(&childCount);
+  AutoTArray<nsCOMPtr<nsIDocShellTreeItem>, 8> kids;
+  kids.AppendElements(childCount);
+  for (int32_t i = 0; i < childCount; ++i) {
+    aItem->GetChildAt(i, getter_AddRefs(kids[i]));
+  }
+
+  for (uint32_t i = 0; i < kids.Length(); ++i) {
+    if (kids[i]) {
+      FirePageShowEvent(kids[i], aChromeEventHandler, aFireIfShowing);
+    }
+  }
+
+  nsCOMPtr<nsIDocument> doc = aItem->GetDocument();
+  NS_ASSERTION(doc, "What happened here?");
+  if (doc->IsShowing() == aFireIfShowing) {
+    doc->OnPageShow(true, aChromeEventHandler);
+  }
+}
+
+/* static */
+already_AddRefed<nsPIWindowRoot>
+nsContentUtils::GetWindowRoot(nsIDocument* aDoc)
+{
+  if (aDoc) {
+    if (nsPIDOMWindowOuter* win = aDoc->GetWindow()) {
+      return win->GetTopWindowRoot();
+    }
+  }
+  return nullptr;
+}
+
+/* static */
+nsContentPolicyType
+nsContentUtils::InternalContentPolicyTypeToExternal(nsContentPolicyType aType)
+{
+  switch (aType) {
+  case nsIContentPolicy::TYPE_INTERNAL_SCRIPT:
+  case nsIContentPolicy::TYPE_INTERNAL_SCRIPT_PRELOAD:
+  case nsIContentPolicy::TYPE_INTERNAL_WORKER:
+  case nsIContentPolicy::TYPE_INTERNAL_SHARED_WORKER:
+  case nsIContentPolicy::TYPE_INTERNAL_SERVICE_WORKER:
+    return nsIContentPolicy::TYPE_SCRIPT;
+
+  case nsIContentPolicy::TYPE_INTERNAL_EMBED:
+  case nsIContentPolicy::TYPE_INTERNAL_OBJECT:
+    return nsIContentPolicy::TYPE_OBJECT;
+
+  case nsIContentPolicy::TYPE_INTERNAL_FRAME:
+  case nsIContentPolicy::TYPE_INTERNAL_IFRAME:
+    return nsIContentPolicy::TYPE_SUBDOCUMENT;
+
+  case nsIContentPolicy::TYPE_INTERNAL_AUDIO:
+  case nsIContentPolicy::TYPE_INTERNAL_VIDEO:
+  case nsIContentPolicy::TYPE_INTERNAL_TRACK:
+    return nsIContentPolicy::TYPE_MEDIA;
+
+  case nsIContentPolicy::TYPE_INTERNAL_XMLHTTPREQUEST:
+  case nsIContentPolicy::TYPE_INTERNAL_EVENTSOURCE:
+    return nsIContentPolicy::TYPE_XMLHTTPREQUEST;
+
+  case nsIContentPolicy::TYPE_INTERNAL_IMAGE:
+  case nsIContentPolicy::TYPE_INTERNAL_IMAGE_PRELOAD:
+  case nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON:
+    return nsIContentPolicy::TYPE_IMAGE;
+
+  case nsIContentPolicy::TYPE_INTERNAL_STYLESHEET:
+  case nsIContentPolicy::TYPE_INTERNAL_STYLESHEET_PRELOAD:
+    return nsIContentPolicy::TYPE_STYLESHEET;
+
+  default:
+    return aType;
+  }
+}
+
+/* static */
+nsContentPolicyType
+nsContentUtils::InternalContentPolicyTypeToExternalOrWorker(nsContentPolicyType aType)
+{
+  switch (aType) {
+  case nsIContentPolicy::TYPE_INTERNAL_WORKER:
+  case nsIContentPolicy::TYPE_INTERNAL_SHARED_WORKER:
+  case nsIContentPolicy::TYPE_INTERNAL_SERVICE_WORKER:
+    return aType;
+
+  default:
+    return InternalContentPolicyTypeToExternal(aType);
+  }
+}
+
+/* static */
+bool
+nsContentUtils::IsPreloadType(nsContentPolicyType aType)
+{
+  if (aType == nsIContentPolicy::TYPE_INTERNAL_SCRIPT_PRELOAD ||
+      aType == nsIContentPolicy::TYPE_INTERNAL_IMAGE_PRELOAD ||
+      aType == nsIContentPolicy::TYPE_INTERNAL_STYLESHEET_PRELOAD) {
+    return true;
+  }
+  return false;
+}
+
+nsresult
+nsContentUtils::SetFetchReferrerURIWithPolicy(nsIPrincipal* aPrincipal,
+                                              nsIDocument* aDoc,
+                                              nsIHttpChannel* aChannel,
+                                              mozilla::net::ReferrerPolicy aReferrerPolicy)
+{
+  NS_ENSURE_ARG_POINTER(aPrincipal);
+  NS_ENSURE_ARG_POINTER(aChannel);
+
+  nsCOMPtr<nsIURI> principalURI;
+
+  if (IsSystemPrincipal(aPrincipal)) {
+    return NS_OK;
+  }
+
+  aPrincipal->GetURI(getter_AddRefs(principalURI));
+
+  if (!aDoc) {
+    return aChannel->SetReferrerWithPolicy(principalURI, aReferrerPolicy);
+  }
+
+  // If it weren't for history.push/replaceState, we could just use the
+  // principal's URI here.  But since we want changes to the URI effected
+  // by push/replaceState to be reflected in the XHR referrer, we have to
+  // be more clever.
+  //
+  // If the document's original URI (before any push/replaceStates) matches
+  // our principal, then we use the document's current URI (after
+  // push/replaceStates).  Otherwise (if the document is, say, a data:
+  // URI), we just use the principal's URI.
+  nsCOMPtr<nsIURI> docCurURI = aDoc->GetDocumentURI();
+  nsCOMPtr<nsIURI> docOrigURI = aDoc->GetOriginalURI();
+
+  nsCOMPtr<nsIURI> referrerURI;
+
+  if (principalURI && docCurURI && docOrigURI) {
+    bool equal = false;
+    principalURI->Equals(docOrigURI, &equal);
+    if (equal) {
+      referrerURI = docCurURI;
+    }
+  }
+
+  if (!referrerURI) {
+    referrerURI = principalURI;
+  }
+
+  net::ReferrerPolicy referrerPolicy = aReferrerPolicy;
+  if (referrerPolicy == net::RP_Default) {
+    referrerPolicy = aDoc->GetReferrerPolicy();
+  }
+  return aChannel->SetReferrerWithPolicy(referrerURI, referrerPolicy);
+}
+
+// static
+net::ReferrerPolicy
+nsContentUtils::GetReferrerPolicyFromHeader(const nsAString& aHeader)
+{
+  // Multiple headers could be concatenated into one comma-separated
+  // list of policies. Need to tokenize the multiple headers.
+  nsCharSeparatedTokenizer tokenizer(aHeader, ',');
+  nsAutoString token;
+  net::ReferrerPolicy referrerPolicy = mozilla::net::RP_Unset;
+  while (tokenizer.hasMoreTokens()) {
+    token = tokenizer.nextToken();
+    net::ReferrerPolicy policy = net::ReferrerPolicyFromString(token);
+    if (policy != net::RP_Unset) {
+      referrerPolicy = policy;
+    }
+  }
+  return referrerPolicy;
+}
+
+// static
+bool
+nsContentUtils::PushEnabled(JSContext* aCx, JSObject* aObj)
+{
+  if (NS_IsMainThread()) {
+    return Preferences::GetBool("dom.push.enabled", false);
+  }
+
+  using namespace workers;
+
+  // Otherwise, check the pref via the WorkerPrivate
+  WorkerPrivate* workerPrivate = GetWorkerPrivateFromContext(aCx);
+  if (!workerPrivate) {
+    return false;
+  }
+
+  return workerPrivate->PushEnabled();
+}
+
+// static
+bool
+nsContentUtils::IsNonSubresourceRequest(nsIChannel* aChannel)
+{
+  nsLoadFlags loadFlags = 0;
+  aChannel->GetLoadFlags(&loadFlags);
+  if (loadFlags & nsIChannel::LOAD_DOCUMENT_URI) {
+    return true;
+  }
+
+  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->GetLoadInfo();
+  if (!loadInfo) {
+    return false;
+  }
+  nsContentPolicyType type = loadInfo->InternalContentPolicyType();
+  return type == nsIContentPolicy::TYPE_INTERNAL_WORKER ||
+         type == nsIContentPolicy::TYPE_INTERNAL_SHARED_WORKER;
+}
+
+// static, public
+nsContentUtils::StorageAccess
+nsContentUtils::StorageAllowedForWindow(nsPIDOMWindowInner* aWindow)
+{
+  MOZ_ASSERT(aWindow->IsInnerWindow());
+
+  if (nsIDocument* document = aWindow->GetExtantDoc()) {
+    nsCOMPtr<nsIPrincipal> principal = document->NodePrincipal();
+    return InternalStorageAllowedForPrincipal(principal, aWindow);
+  }
+
+  return StorageAccess::eDeny;
+}
+
+// static, public
+nsContentUtils::StorageAccess
+nsContentUtils::StorageAllowedForPrincipal(nsIPrincipal* aPrincipal)
+{
+  return InternalStorageAllowedForPrincipal(aPrincipal, nullptr);
+}
+
+// static, private
+nsContentUtils::StorageAccess
+nsContentUtils::InternalStorageAllowedForPrincipal(nsIPrincipal* aPrincipal,
+                                                   nsPIDOMWindowInner* aWindow)
+{
+  MOZ_ASSERT(aPrincipal);
+  MOZ_ASSERT(!aWindow || aWindow->IsInnerWindow());
+
+  StorageAccess access = StorageAccess::eAllow;
+
+  // We don't allow storage on the null principal, in general. Even if the
+  // calling context is chrome.
+  if (aPrincipal->GetIsNullPrincipal()) {
+    return StorageAccess::eDeny;
+  }
+
+  if (aWindow) {
+    // If the document is sandboxed, then it is not permitted to use storage
+    nsIDocument* document = aWindow->GetExtantDoc();
+    if (document->GetSandboxFlags() & SANDBOXED_ORIGIN) {
+      return StorageAccess::eDeny;
+    }
+
+    // Check if we are in private browsing, and record that fact
+    if (IsInPrivateBrowsing(document)) {
+      access = StorageAccess::ePrivateBrowsing;
+    }
+  }
+
+  nsCOMPtr<nsIPermissionManager> permissionManager =
+    services::GetPermissionManager();
+  if (!permissionManager) {
+    return StorageAccess::eDeny;
+  }
+
+  // check the permission manager for any allow or deny permissions
+  // for cookies for the window.
+  uint32_t perm;
+  permissionManager->TestPermissionFromPrincipal(aPrincipal, "cookie", &perm);
+  if (perm == nsIPermissionManager::DENY_ACTION) {
+    return StorageAccess::eDeny;
+  } else if (perm == nsICookiePermission::ACCESS_SESSION) {
+    return std::min(access, StorageAccess::eSessionScoped);
+  } else if (perm == nsIPermissionManager::ALLOW_ACTION) {
+    return access;
+  }
+
+  // Check if we should only allow storage for the session, and record that fact
+  if (sCookiesLifetimePolicy == nsICookieService::ACCEPT_SESSION) {
+    // Storage could be StorageAccess::ePrivateBrowsing or StorageAccess::eAllow
+    // so perform a std::min comparison to make sure we preserve ePrivateBrowsing
+    // if it has been set.
+    access = std::min(StorageAccess::eSessionScoped, access);
+  }
+
+  // About URIs are allowed to access storage, even if they don't have chrome
+  // privileges. If this is not desired, than the consumer will have to
+  // implement their own restriction functionality.
+  //
+  // This is due to backwards-compatibility and the state of storage access before
+  // the introducton of nsContentUtils::InternalStorageAllowedForPrincipal:
+  //
+  // BEFORE:
+  // localStorage, caches: allowed in 3rd-party iframes always
+  // IndexedDB: allowed in 3rd-party iframes only if 3rd party URI is an about:
+  //   URI within a specific whitelist
+  //
+  // AFTER:
+  // localStorage, caches: allowed in 3rd-party iframes by default. Preference
+  //   can be set to disable in 3rd-party, which will not disallow in about: URIs.
+  // IndexedDB: allowed in 3rd-party iframes by default. Preference can be set to
+  //   disable in 3rd-party, which will disallow in about: URIs, unless they are
+  //   within a specific whitelist.
+  //
+  // This means that behavior for storage with internal about: URIs should not be
+  // affected, which is desireable due to the lack of automated testing for about:
+  // URIs with these preferences set, and the importance of the correct functioning
+  // of these URIs even with custom preferences.
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = aPrincipal->GetURI(getter_AddRefs(uri));
+  if (NS_SUCCEEDED(rv) && uri) {
+    bool isAbout = false;
+    MOZ_ALWAYS_SUCCEEDS(uri->SchemeIs("about", &isAbout));
+    if (isAbout) {
+      return access;
+    }
+  }
+
+  // We don't want to prompt for every attempt to access permissions.
+  if (sCookiesBehavior == nsICookieService::BEHAVIOR_REJECT) {
+    return StorageAccess::eDeny;
+  }
+
+  // In the absense of a window, we assume that we are first-party.
+  if (aWindow && (sCookiesBehavior == nsICookieService::BEHAVIOR_REJECT_FOREIGN ||
+                  sCookiesBehavior == nsICookieService::BEHAVIOR_LIMIT_FOREIGN)) {
+    nsCOMPtr<mozIThirdPartyUtil> thirdPartyUtil =
+      do_GetService(THIRDPARTYUTIL_CONTRACTID);
+    MOZ_ASSERT(thirdPartyUtil);
+
+    bool thirdPartyWindow = false;
+    if (NS_SUCCEEDED(thirdPartyUtil->IsThirdPartyWindow(
+          aWindow->GetOuterWindow(), nullptr, &thirdPartyWindow)) && thirdPartyWindow) {
+      // XXX For non-cookie forms of storage, we handle BEHAVIOR_LIMIT_FOREIGN by
+      // simply rejecting the request to use the storage. In the future, if we
+      // change the meaning of BEHAVIOR_LIMIT_FOREIGN to be one which makes sense
+      // for non-cookie storage types, this may change.
+
+      return StorageAccess::eDeny;
+    }
+  }
+
+  return access;
+}
+
+namespace {
+
+// We put StringBuilder in the anonymous namespace to prevent anything outside
+// this file from accidentally being linked against it.
+
+class StringBuilder
+{
+private:
+  // Try to keep the size of StringBuilder close to a jemalloc bucket size.
+  static const uint32_t STRING_BUFFER_UNITS = 1020;
+  class Unit
+  {
+  public:
+    Unit() : mAtom(nullptr), mType(eUnknown), mLength(0)
+    {
+      MOZ_COUNT_CTOR(StringBuilder::Unit);
+    }
+    ~Unit()
+    {
+      if (mType == eString || mType == eStringWithEncode) {
+        delete mString;
+      }
+      MOZ_COUNT_DTOR(StringBuilder::Unit);
+    }
+
+    enum Type
+    {
+      eUnknown,
+      eAtom,
+      eString,
+      eStringWithEncode,
+      eLiteral,
+      eTextFragment,
+      eTextFragmentWithEncode,
+    };
+
+    union
+    {
+      nsIAtom*              mAtom;
+      const char*           mLiteral;
+      nsAutoString*         mString;
+      const nsTextFragment* mTextFragment;
+    };
+    Type     mType;
+    uint32_t mLength;
+  };
+public:
+  StringBuilder() : mLast(this), mLength(0)
+  {
+    MOZ_COUNT_CTOR(StringBuilder);
+  }
+
+  ~StringBuilder()
+  {
+    MOZ_COUNT_DTOR(StringBuilder);
+  }
+
+  void Append(nsIAtom* aAtom)
+  {
+    Unit* u = AddUnit();
+    u->mAtom = aAtom;
+    u->mType = Unit::eAtom;
+    uint32_t len = aAtom->GetLength();
+    u->mLength = len;
+    mLength += len;
+  }
+
+  template<int N>
+  void Append(const char (&aLiteral)[N])
+  {
+    Unit* u = AddUnit();
+    u->mLiteral = aLiteral;
+    u->mType = Unit::eLiteral;
+    uint32_t len = N - 1;
+    u->mLength = len;
+    mLength += len;
+  }
+
+  template<int N>
+  void Append(char (&aLiteral)[N])
+  {
+    Unit* u = AddUnit();
+    u->mLiteral = aLiteral;
+    u->mType = Unit::eLiteral;
+    uint32_t len = N - 1;
+    u->mLength = len;
+    mLength += len;
+  }
+
+  void Append(const nsAString& aString)
+  {
+    Unit* u = AddUnit();
+    u->mString = new nsAutoString(aString);
+    u->mType = Unit::eString;
+    uint32_t len = aString.Length();
+    u->mLength = len;
+    mLength += len;
+  }
+
+  void Append(nsAutoString* aString)
+  {
+    Unit* u = AddUnit();
+    u->mString = aString;
+    u->mType = Unit::eString;
+    uint32_t len = aString->Length();
+    u->mLength = len;
+    mLength += len;
+  }
+
+  void AppendWithAttrEncode(nsAutoString* aString, uint32_t aLen)
+  {
+    Unit* u = AddUnit();
+    u->mString = aString;
+    u->mType = Unit::eStringWithEncode;
+    u->mLength = aLen;
+    mLength += aLen;
+  }
+
+  void Append(const nsTextFragment* aTextFragment)
+  {
+    Unit* u = AddUnit();
+    u->mTextFragment = aTextFragment;
+    u->mType = Unit::eTextFragment;
+    uint32_t len = aTextFragment->GetLength();
+    u->mLength = len;
+    mLength += len;
+  }
+
+  void AppendWithEncode(const nsTextFragment* aTextFragment, uint32_t aLen)
+  {
+    Unit* u = AddUnit();
+    u->mTextFragment = aTextFragment;
+    u->mType = Unit::eTextFragmentWithEncode;
+    u->mLength = aLen;
+    mLength += aLen;
+  }
+
+  bool ToString(nsAString& aOut)
+  {
+    if (!aOut.SetCapacity(mLength, fallible)) {
+      return false;
+    }
+
+    for (StringBuilder* current = this; current; current = current->mNext) {
+      uint32_t len = current->mUnits.Length();
+      for (uint32_t i = 0; i < len; ++i) {
+        Unit& u = current->mUnits[i];
+        switch (u.mType) {
+          case Unit::eAtom:
+            aOut.Append(nsDependentAtomString(u.mAtom));
+            break;
+          case Unit::eString:
+            aOut.Append(*(u.mString));
+            break;
+          case Unit::eStringWithEncode:
+            EncodeAttrString(*(u.mString), aOut);
+            break;
+          case Unit::eLiteral:
+            aOut.AppendASCII(u.mLiteral, u.mLength);
+            break;
+          case Unit::eTextFragment:
+            u.mTextFragment->AppendTo(aOut);
+            break;
+          case Unit::eTextFragmentWithEncode:
+            EncodeTextFragment(u.mTextFragment, aOut);
+            break;
+          default:
+            MOZ_CRASH("Unknown unit type?");
+        }
+      }
+    }
+    return true;
+  }
+private:
+  Unit* AddUnit()
+  {
+    if (mLast->mUnits.Length() == STRING_BUFFER_UNITS) {
+      new StringBuilder(this);
+    }
+    return mLast->mUnits.AppendElement();
+  }
+
+  explicit StringBuilder(StringBuilder* aFirst)
+  : mLast(nullptr), mLength(0)
+  {
+    MOZ_COUNT_CTOR(StringBuilder);
+    aFirst->mLast->mNext = this;
+    aFirst->mLast = this;
+  }
+
+  void EncodeAttrString(const nsAutoString& aValue, nsAString& aOut)
+  {
+    const char16_t* c = aValue.BeginReading();
+    const char16_t* end = aValue.EndReading();
+    while (c < end) {
+      switch (*c) {
+      case '"':
+        aOut.AppendLiteral("&quot;");
+        break;
+      case '&':
+        aOut.AppendLiteral("&amp;");
+        break;
+      case 0x00A0:
+        aOut.AppendLiteral("&nbsp;");
+        break;
+      default:
+        aOut.Append(*c);
+        break;
+      }
+      ++c;
+    }
+  }
+
+  void EncodeTextFragment(const nsTextFragment* aValue, nsAString& aOut)
+  {
+    uint32_t len = aValue->GetLength();
+    if (aValue->Is2b()) {
+      const char16_t* data = aValue->Get2b();
+      for (uint32_t i = 0; i < len; ++i) {
+        const char16_t c = data[i];
+        switch (c) {
+          case '<':
+            aOut.AppendLiteral("&lt;");
+            break;
+          case '>':
+            aOut.AppendLiteral("&gt;");
+            break;
+          case '&':
+            aOut.AppendLiteral("&amp;");
+            break;
+          case 0x00A0:
+            aOut.AppendLiteral("&nbsp;");
+            break;
+          default:
+            aOut.Append(c);
+            break;
+        }
+      }
+    } else {
+      const char* data = aValue->Get1b();
+      for (uint32_t i = 0; i < len; ++i) {
+        const unsigned char c = data[i];
+        switch (c) {
+          case '<':
+            aOut.AppendLiteral("&lt;");
+            break;
+          case '>':
+            aOut.AppendLiteral("&gt;");
+            break;
+          case '&':
+            aOut.AppendLiteral("&amp;");
+            break;
+          case 0x00A0:
+            aOut.AppendLiteral("&nbsp;");
+            break;
+          default:
+            aOut.Append(c);
+            break;
+        }
+      }
+    }
+  }
+
+  AutoTArray<Unit, STRING_BUFFER_UNITS> mUnits;
+  nsAutoPtr<StringBuilder>                mNext;
+  StringBuilder*                          mLast;
+  // mLength is used only in the first StringBuilder object in the linked list.
+  uint32_t                                mLength;
+};
+
+} // namespace
+
+static void
+AppendEncodedCharacters(const nsTextFragment* aText, StringBuilder& aBuilder)
+{
+  uint32_t extraSpaceNeeded = 0;
+  uint32_t len = aText->GetLength();
+  if (aText->Is2b()) {
+    const char16_t* data = aText->Get2b();
+    for (uint32_t i = 0; i < len; ++i) {
+      const char16_t c = data[i];
+      switch (c) {
+        case '<':
+          extraSpaceNeeded += ArrayLength("&lt;") - 2;
+          break;
+        case '>':
+          extraSpaceNeeded += ArrayLength("&gt;") - 2;
+          break;
+        case '&':
+          extraSpaceNeeded += ArrayLength("&amp;") - 2;
+          break;
+        case 0x00A0:
+          extraSpaceNeeded += ArrayLength("&nbsp;") - 2;
+          break;
+        default:
+          break;
+      }
+    }
+  } else {
+    const char* data = aText->Get1b();
+    for (uint32_t i = 0; i < len; ++i) {
+      const unsigned char c = data[i];
+      switch (c) {
+        case '<':
+          extraSpaceNeeded += ArrayLength("&lt;") - 2;
+          break;
+        case '>':
+          extraSpaceNeeded += ArrayLength("&gt;") - 2;
+          break;
+        case '&':
+          extraSpaceNeeded += ArrayLength("&amp;") - 2;
+          break;
+        case 0x00A0:
+          extraSpaceNeeded += ArrayLength("&nbsp;") - 2;
+          break;
+        default:
+          break;
+      }
+    }
+  }
+
+  if (extraSpaceNeeded) {
+    aBuilder.AppendWithEncode(aText, len + extraSpaceNeeded);
+  } else {
+    aBuilder.Append(aText);
+  }
+}
+
+static void
+AppendEncodedAttributeValue(nsAutoString* aValue, StringBuilder& aBuilder)
+{
+  const char16_t* c = aValue->BeginReading();
+  const char16_t* end = aValue->EndReading();
+
+  uint32_t extraSpaceNeeded = 0;
+  while (c < end) {
+    switch (*c) {
+      case '"':
+        extraSpaceNeeded += ArrayLength("&quot;") - 2;
+        break;
+      case '&':
+        extraSpaceNeeded += ArrayLength("&amp;") - 2;
+        break;
+      case 0x00A0:
+        extraSpaceNeeded += ArrayLength("&nbsp;") - 2;
+        break;
+      default:
+        break;
+    }
+    ++c;
+  }
+
+  if (extraSpaceNeeded) {
+    aBuilder.AppendWithAttrEncode(aValue, aValue->Length() + extraSpaceNeeded);
+  } else {
+    aBuilder.Append(aValue);
+  }
+}
+
+static void
+StartElement(Element* aContent, StringBuilder& aBuilder)
+{
+  nsIAtom* localName = aContent->NodeInfo()->NameAtom();
+  int32_t tagNS = aContent->GetNameSpaceID();
+
+  aBuilder.Append("<");
+  if (aContent->IsHTMLElement() || aContent->IsSVGElement() ||
+      aContent->IsMathMLElement()) {
+    aBuilder.Append(localName);
+  } else {
+    aBuilder.Append(aContent->NodeName());
+  }
+
+  int32_t count = aContent->GetAttrCount();
+  for (int32_t i = 0; i < count; i++) {
+    const nsAttrName* name = aContent->GetAttrNameAt(i);
+    int32_t attNs = name->NamespaceID();
+    nsIAtom* attName = name->LocalName();
+
+    // Filter out any attribute starting with [-|_]moz
+    nsDependentAtomString attrNameStr(attName);
+    if (StringBeginsWith(attrNameStr, NS_LITERAL_STRING("_moz")) ||
+        StringBeginsWith(attrNameStr, NS_LITERAL_STRING("-moz"))) {
+      continue;
+    }
+
+    nsAutoString* attValue = new nsAutoString();
+    aContent->GetAttr(attNs, attName, *attValue);
+
+    // Filter out special case of <br type="_moz*"> used by the editor.
+    // Bug 16988.  Yuck.
+    if (localName == nsGkAtoms::br && tagNS == kNameSpaceID_XHTML &&
+        attName == nsGkAtoms::type && attNs == kNameSpaceID_None &&
+        StringBeginsWith(*attValue, NS_LITERAL_STRING("_moz"))) {
+      delete attValue;
+      continue;
+    }
+
+    aBuilder.Append(" ");
+
+    if (MOZ_LIKELY(attNs == kNameSpaceID_None) ||
+        (attNs == kNameSpaceID_XMLNS &&
+         attName == nsGkAtoms::xmlns)) {
+      // Nothing else required
+    } else if (attNs == kNameSpaceID_XML) {
+      aBuilder.Append("xml:");
+    } else if (attNs == kNameSpaceID_XMLNS) {
+      aBuilder.Append("xmlns:");
+    } else if (attNs == kNameSpaceID_XLink) {
+      aBuilder.Append("xlink:");
+    } else {
+      nsIAtom* prefix = name->GetPrefix();
+      if (prefix) {
+        aBuilder.Append(prefix);
+        aBuilder.Append(":");
+      }
+    }
+
+    aBuilder.Append(attName);
+    aBuilder.Append("=\"");
+    AppendEncodedAttributeValue(attValue, aBuilder);
+    aBuilder.Append("\"");
+  }
+
+  aBuilder.Append(">");
+
+  /*
+  // Per HTML spec we should append one \n if the first child of
+  // pre/textarea/listing is a textnode and starts with a \n.
+  // But because browsers haven't traditionally had that behavior,
+  // we're not changing our behavior either - yet.
+  if (aContent->IsHTMLElement()) {
+    if (localName == nsGkAtoms::pre || localName == nsGkAtoms::textarea ||
+        localName == nsGkAtoms::listing) {
+      nsIContent* fc = aContent->GetFirstChild();
+      if (fc &&
+          (fc->NodeType() == nsIDOMNode::TEXT_NODE ||
+           fc->NodeType() == nsIDOMNode::CDATA_SECTION_NODE)) {
+        const nsTextFragment* text = fc->GetText();
+        if (text && text->GetLength() && text->CharAt(0) == char16_t('\n')) {
+          aBuilder.Append("\n");
+        }
+      }
+    }
+  }*/
+}
+
+static inline bool
+ShouldEscape(nsIContent* aParent)
+{
+  if (!aParent || !aParent->IsHTMLElement()) {
+    return true;
+  }
+
+  static const nsIAtom* nonEscapingElements[] = {
+    nsGkAtoms::style, nsGkAtoms::script, nsGkAtoms::xmp,
+    nsGkAtoms::iframe, nsGkAtoms::noembed, nsGkAtoms::noframes,
+    nsGkAtoms::plaintext,
+    // Per the current spec noscript should be escaped in case
+    // scripts are disabled or if document doesn't have
+    // browsing context. However the latter seems to be a spec bug
+    // and Gecko hasn't traditionally done the former.
+    nsGkAtoms::noscript
+  };
+  static mozilla::BloomFilter<12, nsIAtom> sFilter;
+  static bool sInitialized = false;
+  if (!sInitialized) {
+    sInitialized = true;
+    for (uint32_t i = 0; i < ArrayLength(nonEscapingElements); ++i) {
+      sFilter.add(nonEscapingElements[i]);
+    }
+  }
+
+  nsIAtom* tag = aParent->NodeInfo()->NameAtom();
+  if (sFilter.mightContain(tag)) {
+    for (uint32_t i = 0; i < ArrayLength(nonEscapingElements); ++i) {
+      if (tag == nonEscapingElements[i]) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+static inline bool
+IsVoidTag(Element* aElement)
+{
+  if (!aElement->IsHTMLElement()) {
+    return false;
+  }
+  return FragmentOrElement::IsHTMLVoid(aElement->NodeInfo()->NameAtom());
+}
+
+bool
+nsContentUtils::SerializeNodeToMarkup(nsINode* aRoot,
+                                      bool aDescendentsOnly,
+                                      nsAString& aOut)
+{
+  // If you pass in a DOCUMENT_NODE, you must pass aDescendentsOnly as true
+  MOZ_ASSERT(aDescendentsOnly ||
+             aRoot->NodeType() != nsIDOMNode::DOCUMENT_NODE);
+
+  nsINode* current = aDescendentsOnly ?
+    nsNodeUtils::GetFirstChildOfTemplateOrNode(aRoot) : aRoot;
+
+  if (!current) {
+    return true;
+  }
+
+  StringBuilder builder;
+  nsIContent* next;
+  while (true) {
+    bool isVoid = false;
+    switch (current->NodeType()) {
+      case nsIDOMNode::ELEMENT_NODE: {
+        Element* elem = current->AsElement();
+        StartElement(elem, builder);
+        isVoid = IsVoidTag(elem);
+        if (!isVoid &&
+            (next = nsNodeUtils::GetFirstChildOfTemplateOrNode(current))) {
+          current = next;
+          continue;
+        }
+        break;
+      }
+
+      case nsIDOMNode::TEXT_NODE:
+      case nsIDOMNode::CDATA_SECTION_NODE: {
+        const nsTextFragment* text = static_cast<nsIContent*>(current)->GetText();
+        nsIContent* parent = current->GetParent();
+        if (ShouldEscape(parent)) {
+          AppendEncodedCharacters(text, builder);
+        } else {
+          builder.Append(text);
+        }
+        break;
+      }
+
+      case nsIDOMNode::COMMENT_NODE: {
+        builder.Append("<!--");
+        builder.Append(static_cast<nsIContent*>(current)->GetText());
+        builder.Append("-->");
+        break;
+      }
+
+      case nsIDOMNode::DOCUMENT_TYPE_NODE: {
+        builder.Append("<!DOCTYPE ");
+        builder.Append(current->NodeName());
+        builder.Append(">");
+        break;
+      }
+
+      case nsIDOMNode::PROCESSING_INSTRUCTION_NODE: {
+        builder.Append("<?");
+        builder.Append(current->NodeName());
+        builder.Append(" ");
+        builder.Append(static_cast<nsIContent*>(current)->GetText());
+        builder.Append(">");
+        break;
+      }
+    }
+
+    while (true) {
+      if (!isVoid && current->NodeType() == nsIDOMNode::ELEMENT_NODE) {
+        builder.Append("</");
+        nsIContent* elem = static_cast<nsIContent*>(current);
+        if (elem->IsHTMLElement() || elem->IsSVGElement() ||
+            elem->IsMathMLElement()) {
+          builder.Append(elem->NodeInfo()->NameAtom());
+        } else {
+          builder.Append(current->NodeName());
+        }
+        builder.Append(">");
+      }
+      isVoid = false;
+
+      if (current == aRoot) {
+        return builder.ToString(aOut);
+      }
+
+      if ((next = current->GetNextSibling())) {
+        current = next;
+        break;
+      }
+
+      current = current->GetParentNode();
+
+      // Handle template element. If the parent is a template's content,
+      // then adjust the parent to be the template element.
+      if (current != aRoot &&
+          current->NodeType() == nsIDOMNode::DOCUMENT_FRAGMENT_NODE) {
+        DocumentFragment* frag = static_cast<DocumentFragment*>(current);
+        nsIContent* fragHost = frag->GetHost();
+        if (fragHost && nsNodeUtils::IsTemplateElement(fragHost)) {
+          current = fragHost;
+        }
+      }
+
+      if (aDescendentsOnly && current == aRoot) {
+        return builder.ToString(aOut);
+      }
+    }
+  }
+}
+
+bool
+nsContentUtils::IsSpecificAboutPage(JSObject* aGlobal, const char* aUri)
+{
+  // aUri must start with about: or this isn't the right function to be using.
+  MOZ_ASSERT(strncmp(aUri, "about:", 6) == 0);
+
+  // Make sure the global is a window
+  nsGlobalWindow* win = xpc::WindowGlobalOrNull(aGlobal);
+  if (!win) {
+    return false;
+  }
+
+  nsCOMPtr<nsIPrincipal> principal = win->GetPrincipal();
+  NS_ENSURE_TRUE(principal, false);
+  nsCOMPtr<nsIURI> uri;
+  principal->GetURI(getter_AddRefs(uri));
+  if (!uri) {
+    return false;
+  }
+
+  // First check the scheme to avoid getting long specs in the common case.
+  bool isAbout = false;
+  uri->SchemeIs("about", &isAbout);
+  if (!isAbout) {
+    return false;
+  }
+
+  // Now check the spec itself
+  nsAutoCString spec;
+  uri->GetSpecIgnoringRef(spec);
+  return spec.EqualsASCII(aUri);
+}
+
+/* static */ void
+nsContentUtils::SetScrollbarsVisibility(nsIDocShell* aDocShell, bool aVisible)
+{
+  nsCOMPtr<nsIScrollable> scroller = do_QueryInterface(aDocShell);
+
+  if (scroller) {
+    int32_t prefValue;
+
+    if (aVisible) {
+      prefValue = nsIScrollable::Scrollbar_Auto;
+    } else {
+      prefValue = nsIScrollable::Scrollbar_Never;
+    }
+
+    scroller->SetDefaultScrollbarPreferences(
+                nsIScrollable::ScrollOrientation_Y, prefValue);
+    scroller->SetDefaultScrollbarPreferences(
+                nsIScrollable::ScrollOrientation_X, prefValue);
+  }
+}
+
+/* static */ void
+nsContentUtils::GetPresentationURL(nsIDocShell* aDocShell, nsAString& aPresentationUrl)
+{
+  MOZ_ASSERT(aDocShell);
+
+  // Simulate receiver context for web platform test
+  if (Preferences::GetBool("dom.presentation.testing.simulate-receiver")) {
+    nsCOMPtr<nsIDocument> doc;
+
+    nsCOMPtr<nsPIDOMWindowOuter> docShellWin =
+      do_QueryInterface(aDocShell->GetScriptGlobalObject());
+    if (docShellWin) {
+      doc = docShellWin->GetExtantDoc();
+    }
+
+    if (NS_WARN_IF(!doc)) {
+      return;
+    }
+
+    nsCOMPtr<nsIURI> uri = doc->GetDocumentURI();
+    if (NS_WARN_IF(!uri)) {
+      return;
+    }
+
+    nsAutoCString uriStr;
+    uri->GetSpec(uriStr);
+    aPresentationUrl = NS_ConvertUTF8toUTF16(uriStr);
+    return;
+  }
+
+  if (XRE_IsContentProcess()) {
+    nsCOMPtr<nsIDocShellTreeItem> sameTypeRoot;
+    aDocShell->GetSameTypeRootTreeItem(getter_AddRefs(sameTypeRoot));
+    nsCOMPtr<nsIDocShellTreeItem> root;
+    aDocShell->GetRootTreeItem(getter_AddRefs(root));
+    if (sameTypeRoot.get() == root.get()) {
+      // presentation URL is stored in TabChild for the top most
+      // <iframe mozbrowser> in content process.
+      TabChild* tabChild = TabChild::GetFrom(aDocShell);
+      if (tabChild) {
+        aPresentationUrl = tabChild->PresentationURL();
+      }
+      return;
+    }
+  }
+
+  nsCOMPtr<nsILoadContext> loadContext(do_QueryInterface(aDocShell));
+  nsCOMPtr<nsIDOMElement> topFrameElement;
+  loadContext->GetTopFrameElement(getter_AddRefs(topFrameElement));
+  if (!topFrameElement) {
+    return;
+  }
+
+  topFrameElement->GetAttribute(NS_LITERAL_STRING("mozpresentation"), aPresentationUrl);
+}
+
+/* static */ nsIDocShell*
+nsContentUtils::GetDocShellForEventTarget(EventTarget* aTarget)
+{
+  nsCOMPtr<nsPIDOMWindowInner> innerWindow;
+
+  if (nsCOMPtr<nsINode> node = do_QueryInterface(aTarget)) {
+    bool ignore;
+    innerWindow =
+      do_QueryInterface(node->OwnerDoc()->GetScriptHandlingObject(ignore));
+  } else if ((innerWindow = do_QueryInterface(aTarget))) {
+    // Nothing else to do
+  } else {
+    nsCOMPtr<DOMEventTargetHelper> helper = do_QueryInterface(aTarget);
+    if (helper) {
+      innerWindow = helper->GetOwner();
+    }
+  }
+
+  if (innerWindow) {
+    return innerWindow->GetDocShell();
+  }
+
+  return nullptr;
+}
+
+/*
+ * Note: this function only relates to figuring out HTTPS state, which is an
+ * input to the Secure Context algorithm.  We are not actually implementing any
+ * part of the Secure Context algorithm itself here.
+ *
+ * This is a bit of a hack.  Ideally we'd propagate HTTPS state through
+ * nsIChannel as described in the Fetch and HTML specs, but making channels
+ * know about whether they should inherit HTTPS state, propagating information
+ * about who the channel's "client" is, exposing GetHttpsState API on channels
+ * and modifying the various cache implementations to store and retrieve HTTPS
+ * state involves a huge amount of code (see bug 1220687).  We avoid that for
+ * now using this function.
+ *
+ * This function takes advantage of the observation that we can return true if
+ * nsIContentSecurityManager::IsOriginPotentiallyTrustworthy returns true for
+ * the document's origin (e.g. the origin has a scheme of 'https' or host
+ * 'localhost' etc.).  Since we generally propagate a creator document's origin
+ * onto data:, blob:, etc. documents, this works for them too.
+ *
+ * The scenario where this observation breaks down is sandboxing without the
+ * 'allow-same-origin' flag, since in this case a document is given a unique
+ * origin (IsOriginPotentiallyTrustworthy would return false).  We handle that
+ * by using the origin that the document would have had had it not been
+ * sandboxed.
+ *
+ * DEFICIENCIES: Note that this function uses nsIScriptSecurityManager's
+ * getChannelResultPrincipalIfNotSandboxed, and that method's ignoring of
+ * sandboxing is limited to the immediate sandbox.  In the case that aDocument
+ * should inherit its origin (e.g. data: URI) but its parent has ended up
+ * with a unique origin due to sandboxing further up the parent chain we may
+ * end up returning false when we would ideally return true (since we will
+ * examine the parent's origin for 'https' and not finding it.)  This means
+ * that we may restrict the privileges of some pages unnecessarily in this
+ * edge case.
+ */
+/* static */ bool
+nsContentUtils::HttpsStateIsModern(nsIDocument* aDocument)
+{
+  if (!aDocument) {
+    return false;
+  }
+
+  nsCOMPtr<nsIPrincipal> principal = aDocument->NodePrincipal();
+
+  if (principal->GetIsSystemPrincipal()) {
+    return true;
+  }
+
+  // If aDocument is sandboxed, try and get the principal that it would have
+  // been given had it not been sandboxed:
+  if (principal->GetIsNullPrincipal() &&
+      (aDocument->GetSandboxFlags() & SANDBOXED_ORIGIN)) {
+    nsIChannel* channel = aDocument->GetChannel();
+    if (channel) {
+      nsCOMPtr<nsIScriptSecurityManager> ssm =
+        nsContentUtils::GetSecurityManager();
+      nsresult rv =
+        ssm->GetChannelResultPrincipalIfNotSandboxed(channel,
+                                                     getter_AddRefs(principal));
+      if (NS_FAILED(rv)) {
+        return false;
+      }
+      if (principal->GetIsSystemPrincipal()) {
+        // If a document with the system principal is sandboxing a subdocument
+        // that would normally inherit the embedding element's principal (e.g.
+        // a srcdoc document) then the embedding document does not trust the
+        // content that is written to the embedded document.  Unlike when the
+        // embedding document is https, in this case we have no indication as
+        // to whether the embedded document's contents are delivered securely
+        // or not, and the sandboxing would possibly indicate that they were
+        // not.  To play it safe we return false here.  (See bug 1162772
+        // comment 73-80.)
+        return false;
+      }
+    }
+  }
+
+  if (principal->GetIsNullPrincipal()) {
+    return false;
+  }
+
+  MOZ_ASSERT(principal->GetIsCodebasePrincipal());
+
+  nsCOMPtr<nsIContentSecurityManager> csm =
+    do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
+  NS_WARNING_ASSERTION(csm, "csm is null");
+  if (csm) {
+    bool isTrustworthyOrigin = false;
+    csm->IsOriginPotentiallyTrustworthy(principal, &isTrustworthyOrigin);
+    if (isTrustworthyOrigin) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/* static */ CustomElementDefinition*
+nsContentUtils::LookupCustomElementDefinition(nsIDocument* aDoc,
+                                              const nsAString& aLocalName,
+                                              uint32_t aNameSpaceID,
+                                              const nsAString* aIs)
+{
+  MOZ_ASSERT(aDoc);
+
+  // To support imported document.
+  nsCOMPtr<nsIDocument> doc = aDoc->MasterDocument();
+
+  if (aNameSpaceID != kNameSpaceID_XHTML ||
+      !doc->GetDocShell()) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsPIDOMWindowInner> window(doc->GetInnerWindow());
+  if (!window) {
+    return nullptr;
+  }
+
+  RefPtr<CustomElementRegistry> registry(window->CustomElements());
+  if (!registry) {
+    return nullptr;
+  }
+
+  return registry->LookupCustomElementDefinition(aLocalName, aIs);
+}
+
+/* static */ void
+nsContentUtils::SetupCustomElement(Element* aElement,
+                                   const nsAString* aTypeExtension)
+{
+  MOZ_ASSERT(aElement);
+
+  nsCOMPtr<nsIDocument> doc = aElement->OwnerDoc();
+
+  if (!doc) {
+    return;
+  }
+
+  // To support imported document.
+  doc = doc->MasterDocument();
+
+  if (aElement->GetNameSpaceID() != kNameSpaceID_XHTML ||
+      !doc->GetDocShell()) {
+    return;
+  }
+
+  nsCOMPtr<nsPIDOMWindowInner> window(doc->GetInnerWindow());
+  if (!window) {
+    return;
+  }
+
+  RefPtr<CustomElementRegistry> registry(window->CustomElements());
+  if (!registry) {
+    return;
+  }
+
+  return registry->SetupCustomElement(aElement, aTypeExtension);
+}
+
+/* static */ void
+nsContentUtils::EnqueueLifecycleCallback(nsIDocument* aDoc,
+                                         nsIDocument::ElementCallbackType aType,
+                                         Element* aCustomElement,
+                                         LifecycleCallbackArgs* aArgs,
+                                         CustomElementDefinition* aDefinition)
+{
+  MOZ_ASSERT(aDoc);
+
+  // To support imported document.
+  nsCOMPtr<nsIDocument> doc = aDoc->MasterDocument();
+
+  if (!doc->GetDocShell()) {
+    return;
+  }
+
+  nsCOMPtr<nsPIDOMWindowInner> window(doc->GetInnerWindow());
+  if (!window) {
+    return;
+  }
+
+  RefPtr<CustomElementRegistry> registry(window->CustomElements());
+  if (!registry) {
+    return;
+  }
+
+  registry->EnqueueLifecycleCallback(aType, aCustomElement, aArgs, aDefinition);
+}
+
+/* static */ void
+nsContentUtils::GetCustomPrototype(nsIDocument* aDoc,
+                                   int32_t aNamespaceID,
+                                   nsIAtom* aAtom,
+                                   JS::MutableHandle<JSObject*> aPrototype)
+{
+  MOZ_ASSERT(aDoc);
+
+  // To support imported document.
+  nsCOMPtr<nsIDocument> doc = aDoc->MasterDocument();
+
+  if (aNamespaceID != kNameSpaceID_XHTML ||
+      !doc->GetDocShell()) {
+    return;
+  }
+
+  nsCOMPtr<nsPIDOMWindowInner> window(doc->GetInnerWindow());
+  if (!window) {
+    return;
+  }
+
+  RefPtr<CustomElementRegistry> registry(window->CustomElements());
+  if (!registry) {
+    return;
+  }
+
+  return registry->GetCustomPrototype(aAtom, aPrototype);
+}
+
+/* static */ bool
+nsContentUtils::AttemptLargeAllocationLoad(nsIHttpChannel* aChannel)
+{
+  MOZ_ASSERT(aChannel);
+
+  nsCOMPtr<nsILoadGroup> loadGroup;
+  nsresult rv = aChannel->GetLoadGroup(getter_AddRefs(loadGroup));
+  if (NS_WARN_IF(NS_FAILED(rv) || !loadGroup)) {
+    return false;
+  }
+
+  nsCOMPtr<nsIInterfaceRequestor> callbacks;
+  rv = loadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
+  if (NS_WARN_IF(NS_FAILED(rv) || !callbacks)) {
+    return false;
+  }
+
+  nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(callbacks);
+  if (NS_WARN_IF(!loadContext)) {
+    return false;
+  }
+
+  nsCOMPtr<mozIDOMWindowProxy> window;
+  rv = loadContext->GetAssociatedWindow(getter_AddRefs(window));
+  if (NS_WARN_IF(NS_FAILED(rv) || !window)) {
+    return false;
+  }
+
+  nsPIDOMWindowOuter* outer = nsPIDOMWindowOuter::From(window);
+  if (NS_WARN_IF(!outer)) {
+    return false;
+  }
+
+  nsIDocShell* docShell = outer->GetDocShell();
+  nsIDocument* doc = outer->GetExtantDoc();
+
+  // If the docshell is not allowed to change process, report an error based on
+  // the reason
+  const char* errorName = nullptr;
+  switch (docShell->GetProcessLockReason()) {
+    case nsIDocShell::PROCESS_LOCK_NON_CONTENT:
+      errorName = "LargeAllocationNonE10S";
+      break;
+    case nsIDocShell::PROCESS_LOCK_IFRAME:
+      errorName = "LargeAllocationIFrame";
+      break;
+    case nsIDocShell::PROCESS_LOCK_RELATED_CONTEXTS:
+      errorName = "LargeAllocationRelatedBrowsingContexts";
+      break;
+    case nsIDocShell::PROCESS_LOCK_NONE:
+      // Don't print a warning, we're allowed to change processes!
+      break;
+    default:
+      MOZ_ASSERT(false, "Should be unreachable!");
+      return false;
+  }
+
+  if (errorName) {
+    if (doc) {
+      nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
+                                      NS_LITERAL_CSTRING("DOM"),
+                                      doc,
+                                      nsContentUtils::eDOM_PROPERTIES,
+                                      errorName);
+    }
+
+    return false;
+  }
+
+  // Get the request method, and check if it is a GET request. If it is not GET,
+  // then we cannot perform a large allocation load.
+  nsAutoCString requestMethod;
+  rv = aChannel->GetRequestMethod(requestMethod);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  if (NS_WARN_IF(!requestMethod.LowerCaseEqualsLiteral("get"))) {
+    if (doc) {
+      nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
+                                      NS_LITERAL_CSTRING("DOM"),
+                                      doc,
+                                      nsContentUtils::eDOM_PROPERTIES,
+                                      "LargeAllocationNonGetRequest");
+    }
+    return false;
+  }
+
+  TabChild* tabChild = TabChild::GetFrom(outer);
+  NS_ENSURE_TRUE(tabChild, false);
+
+  if (tabChild->TakeIsFreshProcess())  {
+    NS_WARNING("Already in a fresh process, ignoring Large-Allocation header!");
+    if (doc) {
+      nsContentUtils::ReportToConsole(nsIScriptError::infoFlag,
+                                      NS_LITERAL_CSTRING("DOM"),
+                                      doc,
+                                      nsContentUtils::eDOM_PROPERTIES,
+                                      "LargeAllocationSuccess");
+    }
+    return false;
+  }
+
+  // At this point the fress process load should succeed! We just need to get
+  // ourselves a nsIWebBrowserChrome3 to ask to perform the reload. We should
+  // have one, as we have already confirmed that we are running in a content
+  // process.
+  nsCOMPtr<nsIDocShellTreeOwner> treeOwner;
+  docShell->GetTreeOwner(getter_AddRefs(treeOwner));
+  NS_ENSURE_TRUE(treeOwner, false);
+
+  nsCOMPtr<nsIWebBrowserChrome3> wbc3 = do_GetInterface(treeOwner);
+  NS_ENSURE_TRUE(wbc3, false);
+
+  nsCOMPtr<nsIURI> uri;
+  rv = aChannel->GetURI(getter_AddRefs(uri));
+  NS_ENSURE_SUCCESS(rv, false);
+  NS_ENSURE_TRUE(uri, false);
+
+  nsCOMPtr<nsIURI> referrer;
+  rv = aChannel->GetReferrer(getter_AddRefs(referrer));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  // Actually perform the cross process load
+  bool reloadSucceeded = false;
+  rv = wbc3->ReloadInFreshProcess(docShell, uri, referrer, &reloadSucceeded);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return reloadSucceeded;
+}