Add m-esr52 at 52.6.0

16 files changed, 6383 insertions, 0 deletions

diff --git a/uriloader/prefetch/OfflineCacheUpdateChild.cpp b/uriloader/prefetch/OfflineCacheUpdateChild.cpp
new file mode 100644
index 0000000000..555508c373
--- /dev/null
+++ b/uriloader/prefetch/OfflineCacheUpdateChild.cpp
@@ -0,0 +1,528 @@
+/* -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "BackgroundUtils.h"
+#include "OfflineCacheUpdateChild.h"
+#include "nsOfflineCacheUpdate.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/TabChild.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "mozilla/net/NeckoCommon.h"
+
+#include "nsIApplicationCacheContainer.h"
+#include "nsIApplicationCacheChannel.h"
+#include "nsIApplicationCacheService.h"
+#include "nsIDocShell.h"
+#include "nsIDocShellTreeItem.h"
+#include "nsIDocShellTreeOwner.h"
+#include "nsPIDOMWindow.h"
+#include "nsIDOMOfflineResourceList.h"
+#include "nsIDocument.h"
+#include "nsIObserverService.h"
+#include "nsIURL.h"
+#include "nsITabChild.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsServiceManagerUtils.h"
+#include "nsStreamUtils.h"
+#include "nsThreadUtils.h"
+#include "nsProxyRelease.h"
+#include "mozilla/Logging.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+
+using namespace mozilla::ipc;
+using namespace mozilla::net;
+using mozilla::dom::TabChild;
+using mozilla::dom::ContentChild;
+
+//
+// To enable logging (see mozilla/Logging.h for full details):
+//
+//    set MOZ_LOG=nsOfflineCacheUpdate:5
+//    set MOZ_LOG_FILE=offlineupdate.log
+//
+// this enables LogLevel::Debug level information and places all output in
+// the file offlineupdate.log
+//
+extern mozilla::LazyLogModule gOfflineCacheUpdateLog;
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug, args)
+
+#undef LOG_ENABLED
+#define LOG_ENABLED() MOZ_LOG_TEST(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug)
+
+namespace mozilla {
+namespace docshell {
+
+//-----------------------------------------------------------------------------
+// OfflineCacheUpdateChild::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_INTERFACE_MAP_BEGIN(OfflineCacheUpdateChild)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  NS_INTERFACE_MAP_ENTRY(nsIOfflineCacheUpdate)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_ADDREF(OfflineCacheUpdateChild)
+NS_IMPL_RELEASE(OfflineCacheUpdateChild)
+
+//-----------------------------------------------------------------------------
+// OfflineCacheUpdateChild <public>
+//-----------------------------------------------------------------------------
+
+OfflineCacheUpdateChild::OfflineCacheUpdateChild(nsPIDOMWindowInner* aWindow)
+    : mState(STATE_UNINITIALIZED)
+    , mIsUpgrade(false)
+    , mSucceeded(false)
+    , mWindow(aWindow)
+    , mByteProgress(0)
+{
+}
+
+OfflineCacheUpdateChild::~OfflineCacheUpdateChild()
+{
+    LOG(("OfflineCacheUpdateChild::~OfflineCacheUpdateChild [%p]", this));
+}
+
+void
+OfflineCacheUpdateChild::GatherObservers(nsCOMArray<nsIOfflineCacheUpdateObserver> &aObservers)
+{
+    for (int32_t i = 0; i < mWeakObservers.Count(); i++) {
+        nsCOMPtr<nsIOfflineCacheUpdateObserver> observer =
+            do_QueryReferent(mWeakObservers[i]);
+        if (observer)
+            aObservers.AppendObject(observer);
+        else
+            mWeakObservers.RemoveObjectAt(i--);
+    }
+
+    for (int32_t i = 0; i < mObservers.Count(); i++) {
+        aObservers.AppendObject(mObservers[i]);
+    }
+}
+
+void
+OfflineCacheUpdateChild::SetDocument(nsIDOMDocument *aDocument)
+{
+    // The design is one document for one cache update on the content process.
+    NS_ASSERTION(!mDocument, "Setting more then a single document on a child offline cache update");
+
+    LOG(("Document %p added to update child %p", aDocument, this));
+
+    // Add document only if it was not loaded from an offline cache.
+    // If it were loaded from an offline cache then it has already
+    // been associated with it and must not be again cached as
+    // implicit (which are the reasons we collect documents here).
+    nsCOMPtr<nsIDocument> document = do_QueryInterface(aDocument);
+    if (!document)
+        return;
+
+    nsIChannel* channel = document->GetChannel();
+    nsCOMPtr<nsIApplicationCacheChannel> appCacheChannel =
+        do_QueryInterface(channel);
+    if (!appCacheChannel)
+        return;
+
+    bool loadedFromAppCache;
+    appCacheChannel->GetLoadedFromApplicationCache(&loadedFromAppCache);
+    if (loadedFromAppCache)
+        return;
+
+    mDocument = aDocument;
+}
+
+nsresult
+OfflineCacheUpdateChild::AssociateDocument(nsIDOMDocument *aDocument,
+                                        nsIApplicationCache *aApplicationCache)
+{
+    // Check that the document that requested this update was
+    // previously associated with an application cache.  If not, it
+    // should be associated with the new one.
+    nsCOMPtr<nsIApplicationCacheContainer> container =
+        do_QueryInterface(aDocument);
+    if (!container)
+        return NS_OK;
+
+    nsCOMPtr<nsIApplicationCache> existingCache;
+    nsresult rv = container->GetApplicationCache(getter_AddRefs(existingCache));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!existingCache) {
+        if (LOG_ENABLED()) {
+            nsAutoCString clientID;
+            if (aApplicationCache) {
+                aApplicationCache->GetClientID(clientID);
+            }
+            LOG(("Update %p: associating app cache %s to document %p",
+                 this, clientID.get(), aDocument));
+        }
+
+        rv = container->SetApplicationCache(aApplicationCache);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// OfflineCacheUpdateChild::nsIOfflineCacheUpdate
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::Init(nsIURI *aManifestURI,
+                              nsIURI *aDocumentURI,
+                              nsIPrincipal *aLoadingPrincipal,
+                              nsIDOMDocument *aDocument,
+                              nsIFile *aCustomProfileDir)
+{
+    nsresult rv;
+
+    // Make sure the service has been initialized
+    nsOfflineCacheUpdateService* service =
+        nsOfflineCacheUpdateService::EnsureService();
+    if (!service)
+        return NS_ERROR_FAILURE;
+
+    if (aCustomProfileDir) {
+        NS_ERROR("Custom Offline Cache Update not supported on child process");
+        return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    LOG(("OfflineCacheUpdateChild::Init [%p]", this));
+
+    // Only http and https applications are supported.
+    bool match;
+    rv = aManifestURI->SchemeIs("http", &match);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!match) {
+        rv = aManifestURI->SchemeIs("https", &match);
+        NS_ENSURE_SUCCESS(rv, rv);
+        if (!match)
+            return NS_ERROR_ABORT;
+    }
+
+    mManifestURI = aManifestURI;
+
+    rv = mManifestURI->GetAsciiHost(mUpdateDomain);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mDocumentURI = aDocumentURI;
+    mLoadingPrincipal = aLoadingPrincipal;
+
+    mState = STATE_INITIALIZED;
+
+    if (aDocument)
+        SetDocument(aDocument);
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::InitPartial(nsIURI *aManifestURI,
+                                  const nsACString& clientID,
+                                  nsIURI *aDocumentURI,
+                                  nsIPrincipal *aLoadingPrincipal)
+{
+    NS_NOTREACHED("Not expected to do partial offline cache updates"
+                  " on the child process");
+    // For now leaving this method, we may discover we need it.
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::InitForUpdateCheck(nsIURI *aManifestURI,
+                                            nsIPrincipal* aLoadingPrincipal,
+                                            nsIObserver *aObserver)
+{
+    NS_NOTREACHED("Not expected to do only update checks"
+                  " from the child process");
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::GetUpdateDomain(nsACString &aUpdateDomain)
+{
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    aUpdateDomain = mUpdateDomain;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::GetStatus(uint16_t *aStatus)
+{
+    switch (mState) {
+    case STATE_CHECKING :
+        *aStatus = nsIDOMOfflineResourceList::CHECKING;
+        return NS_OK;
+    case STATE_DOWNLOADING :
+        *aStatus = nsIDOMOfflineResourceList::DOWNLOADING;
+        return NS_OK;
+    default :
+        *aStatus = nsIDOMOfflineResourceList::IDLE;
+        return NS_OK;
+    }
+
+    return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::GetPartial(bool *aPartial)
+{
+    *aPartial = false;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::GetManifestURI(nsIURI **aManifestURI)
+{
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    NS_IF_ADDREF(*aManifestURI = mManifestURI);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::GetSucceeded(bool *aSucceeded)
+{
+    NS_ENSURE_TRUE(mState == STATE_FINISHED, NS_ERROR_NOT_AVAILABLE);
+
+    *aSucceeded = mSucceeded;
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::GetIsUpgrade(bool *aIsUpgrade)
+{
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    *aIsUpgrade = mIsUpgrade;
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::AddDynamicURI(nsIURI *aURI)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::Cancel()
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::AddObserver(nsIOfflineCacheUpdateObserver *aObserver,
+                                  bool aHoldWeak)
+{
+    LOG(("OfflineCacheUpdateChild::AddObserver [%p]", this));
+
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    if (aHoldWeak) {
+        nsCOMPtr<nsIWeakReference> weakRef = do_GetWeakReference(aObserver);
+        mWeakObservers.AppendObject(weakRef);
+    } else {
+        mObservers.AppendObject(aObserver);
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::RemoveObserver(nsIOfflineCacheUpdateObserver *aObserver)
+{
+    LOG(("OfflineCacheUpdateChild::RemoveObserver [%p]", this));
+
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    for (int32_t i = 0; i < mWeakObservers.Count(); i++) {
+        nsCOMPtr<nsIOfflineCacheUpdateObserver> observer =
+            do_QueryReferent(mWeakObservers[i]);
+        if (observer == aObserver) {
+            mWeakObservers.RemoveObjectAt(i);
+            return NS_OK;
+        }
+    }
+
+    for (int32_t i = 0; i < mObservers.Count(); i++) {
+        if (mObservers[i] == aObserver) {
+            mObservers.RemoveObjectAt(i);
+            return NS_OK;
+        }
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::GetByteProgress(uint64_t * _result)
+{
+    NS_ENSURE_ARG(_result);
+
+    *_result = mByteProgress;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateChild::Schedule()
+{
+    LOG(("OfflineCacheUpdateChild::Schedule [%p]", this));
+
+    NS_ASSERTION(mWindow, "Window must be provided to the offline cache update child");
+
+    nsCOMPtr<nsPIDOMWindowInner> window = mWindow.forget();
+    nsCOMPtr<nsIDocShell >docshell = window->GetDocShell();
+    if (!docshell) {
+      NS_WARNING("doc shell tree item is null");
+      return NS_ERROR_FAILURE;
+    }
+
+    nsCOMPtr<nsITabChild> tabchild = docshell->GetTabChild();
+    // because owner implements nsITabChild, we can assume that it is
+    // the one and only TabChild.
+    TabChild* child = tabchild ? static_cast<TabChild*>(tabchild.get()) : nullptr;
+
+    if (MissingRequiredTabChild(child, "offlinecacheupdate")) {
+      return NS_ERROR_FAILURE;
+    }
+
+    URIParams manifestURI, documentURI;
+    SerializeURI(mManifestURI, manifestURI);
+    SerializeURI(mDocumentURI, documentURI);
+
+    nsresult rv = NS_OK;
+    PrincipalInfo loadingPrincipalInfo;
+    rv = PrincipalToPrincipalInfo(mLoadingPrincipal,
+                                  &loadingPrincipalInfo);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+    if (observerService) {
+      LOG(("Calling offline-cache-update-added"));
+      observerService->NotifyObservers(static_cast<nsIOfflineCacheUpdate*>(this),
+                                       "offline-cache-update-added",
+                                       nullptr);
+      LOG(("Done offline-cache-update-added"));
+    }
+
+    // mDocument is non-null if both:
+    // 1. this update was initiated by a document that referred a manifest
+    // 2. the document has not already been loaded from the application cache
+    // This tells the update to cache this document even in case the manifest
+    // has not been changed since the last fetch.
+    // See also nsOfflineCacheUpdate::ScheduleImplicit.
+    bool stickDocument = mDocument != nullptr; 
+
+    // Need to addref ourself here, because the IPC stack doesn't hold
+    // a reference to us. Will be released in RecvFinish() that identifies 
+    // the work has been done.
+    ContentChild::GetSingleton()->SendPOfflineCacheUpdateConstructor(
+        this, manifestURI, documentURI, loadingPrincipalInfo,
+        stickDocument);
+
+    // ContentChild::DeallocPOfflineCacheUpdate will release this.
+    NS_ADDREF_THIS();
+
+    return NS_OK;
+}
+
+bool
+OfflineCacheUpdateChild::RecvAssociateDocuments(const nsCString &cacheGroupId,
+                                                  const nsCString &cacheClientId)
+{
+    LOG(("OfflineCacheUpdateChild::RecvAssociateDocuments [%p, cache=%s]", this, cacheClientId.get()));
+
+    nsresult rv;
+
+    nsCOMPtr<nsIApplicationCache> cache =
+        do_CreateInstance(NS_APPLICATIONCACHE_CONTRACTID, &rv);
+    if (NS_FAILED(rv))
+      return true;
+
+    cache->InitAsHandle(cacheGroupId, cacheClientId);
+
+    if (mDocument) {
+        AssociateDocument(mDocument, cache);
+    }
+
+    nsCOMArray<nsIOfflineCacheUpdateObserver> observers;
+    GatherObservers(observers);
+
+    for (int32_t i = 0; i < observers.Count(); i++)
+        observers[i]->ApplicationCacheAvailable(cache);
+
+    return true;
+}
+
+bool
+OfflineCacheUpdateChild::RecvNotifyStateEvent(const uint32_t &event,
+                                              const uint64_t &byteProgress)
+{
+    LOG(("OfflineCacheUpdateChild::RecvNotifyStateEvent [%p]", this));
+
+    mByteProgress = byteProgress;
+
+    // Convert the public observer state to our internal state
+    switch (event) {
+        case nsIOfflineCacheUpdateObserver::STATE_CHECKING:
+            mState = STATE_CHECKING;
+            break;
+
+        case nsIOfflineCacheUpdateObserver::STATE_DOWNLOADING:
+            mState = STATE_DOWNLOADING;
+            break;
+
+        default:
+            break;
+    }
+
+    nsCOMArray<nsIOfflineCacheUpdateObserver> observers;
+    GatherObservers(observers);
+
+    for (int32_t i = 0; i < observers.Count(); i++)
+        observers[i]->UpdateStateChanged(this, event);
+
+    return true;
+}
+
+bool
+OfflineCacheUpdateChild::RecvFinish(const bool &succeeded,
+                                    const bool &isUpgrade)
+{
+    LOG(("OfflineCacheUpdateChild::RecvFinish [%p]", this));
+
+    RefPtr<OfflineCacheUpdateChild> kungFuDeathGrip(this);
+
+    mState = STATE_FINISHED;
+    mSucceeded = succeeded;
+    mIsUpgrade = isUpgrade;
+
+    nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+    if (observerService) {
+        LOG(("Calling offline-cache-update-completed"));
+        observerService->NotifyObservers(static_cast<nsIOfflineCacheUpdate*>(this),
+                                         "offline-cache-update-completed",
+                                         nullptr);
+        LOG(("Done offline-cache-update-completed"));
+    }
+
+    // This is by contract the last notification from the parent, release
+    // us now. This is corresponding to AddRef in Schedule().
+    // TabChild::DeallocPOfflineCacheUpdate will call Release.
+    OfflineCacheUpdateChild::Send__delete__(this);
+
+    return true;
+}
+
+} // namespace docshell
+} // namespace mozilla
diff --git a/uriloader/prefetch/OfflineCacheUpdateChild.h b/uriloader/prefetch/OfflineCacheUpdateChild.h
new file mode 100644
index 0000000000..89d1e6f1f8
--- /dev/null
+++ b/uriloader/prefetch/OfflineCacheUpdateChild.h
@@ -0,0 +1,94 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#ifndef nsOfflineCacheUpdateChild_h
+#define nsOfflineCacheUpdateChild_h
+
+#include "mozilla/docshell/POfflineCacheUpdateChild.h"
+#include "nsIOfflineCacheUpdate.h"
+
+#include "nsCOMArray.h"
+#include "nsCOMPtr.h"
+#include "nsIDOMDocument.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "nsIURI.h"
+#include "nsString.h"
+#include "nsWeakReference.h"
+
+class nsPIDOMWindowInner;
+
+namespace mozilla {
+namespace docshell {
+
+class OfflineCacheUpdateChild : public nsIOfflineCacheUpdate
+                              , public POfflineCacheUpdateChild
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIOFFLINECACHEUPDATE
+
+    virtual bool
+    RecvNotifyStateEvent(const uint32_t& stateEvent,
+                         const uint64_t& byteProgress) override;
+
+    virtual bool
+    RecvAssociateDocuments(
+            const nsCString& cacheGroupId,
+            const nsCString& cacheClientId) override;
+
+    virtual bool
+    RecvFinish(const bool& succeeded,
+               const bool& isUpgrade) override;
+
+    explicit OfflineCacheUpdateChild(nsPIDOMWindowInner* aWindow);
+
+    void SetDocument(nsIDOMDocument *aDocument);
+
+private:
+    ~OfflineCacheUpdateChild();
+
+    nsresult AssociateDocument(nsIDOMDocument *aDocument,
+                               nsIApplicationCache *aApplicationCache);
+    void GatherObservers(nsCOMArray<nsIOfflineCacheUpdateObserver> &aObservers);
+    nsresult Finish();
+
+    enum {
+        STATE_UNINITIALIZED,
+        STATE_INITIALIZED,
+        STATE_CHECKING,
+        STATE_DOWNLOADING,
+        STATE_CANCELLED,
+        STATE_FINISHED
+    } mState;
+
+    bool mIsUpgrade;
+    bool mSucceeded;
+
+    nsCString mUpdateDomain;
+    nsCOMPtr<nsIURI> mManifestURI;
+    nsCOMPtr<nsIURI> mDocumentURI;
+    nsCOMPtr<nsIPrincipal> mLoadingPrincipal;
+
+    nsCOMPtr<nsIObserverService> mObserverService;
+
+    /* Clients watching this update for changes */
+    nsCOMArray<nsIWeakReference> mWeakObservers;
+    nsCOMArray<nsIOfflineCacheUpdateObserver> mObservers;
+
+    /* Document that requested this update */
+    nsCOMPtr<nsIDOMDocument> mDocument;
+
+    /* Keep reference to the window that owns this update to call the
+       parent offline cache update construcor */
+    nsCOMPtr<nsPIDOMWindowInner> mWindow;
+
+    uint64_t mByteProgress;
+};
+
+} // namespace docshell
+} // namespace mozilla
+
+#endif
diff --git a/uriloader/prefetch/OfflineCacheUpdateGlue.cpp b/uriloader/prefetch/OfflineCacheUpdateGlue.cpp
new file mode 100644
index 0000000000..71ca986ffb
--- /dev/null
+++ b/uriloader/prefetch/OfflineCacheUpdateGlue.cpp
@@ -0,0 +1,228 @@
+/* -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "OfflineCacheUpdateGlue.h"
+#include "nsOfflineCacheUpdate.h"
+#include "mozilla/Services.h"
+
+#include "nsIApplicationCache.h"
+#include "nsIApplicationCacheChannel.h"
+#include "nsIApplicationCacheContainer.h"
+#include "nsIChannel.h"
+#include "nsIDocument.h"
+#include "mozilla/Logging.h"
+
+//
+// To enable logging (see mozilla/Logging.h for full details):
+//
+//    set MOZ_LOG=nsOfflineCacheUpdate:5
+//    set MOZ_LOG_FILE=offlineupdate.log
+//
+// this enables LogLevel::Info level information and places all output in
+// the file offlineupdate.log
+//
+extern mozilla::LazyLogModule gOfflineCacheUpdateLog;
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug, args)
+
+#undef LOG_ENABLED
+#define LOG_ENABLED() MOZ_LOG_TEST(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug)
+
+namespace mozilla {
+namespace docshell {
+
+//-----------------------------------------------------------------------------
+// OfflineCacheUpdateGlue::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(OfflineCacheUpdateGlue,
+                  nsIOfflineCacheUpdate,
+                  nsIOfflineCacheUpdateObserver,
+                  nsISupportsWeakReference)
+
+//-----------------------------------------------------------------------------
+// OfflineCacheUpdateGlue <public>
+//-----------------------------------------------------------------------------
+
+OfflineCacheUpdateGlue::OfflineCacheUpdateGlue()
+: mCoalesced(false)
+{
+    LOG(("OfflineCacheUpdateGlue::OfflineCacheUpdateGlue [%p]", this));
+}
+
+OfflineCacheUpdateGlue::~OfflineCacheUpdateGlue()
+{
+    LOG(("OfflineCacheUpdateGlue::~OfflineCacheUpdateGlue [%p]", this));
+}
+
+nsIOfflineCacheUpdate*
+OfflineCacheUpdateGlue::EnsureUpdate()
+{
+    if (!mUpdate) {
+        mUpdate = new nsOfflineCacheUpdate();
+        LOG(("OfflineCacheUpdateGlue [%p] is using update [%p]", this, mUpdate.get()));
+    }
+
+    return mUpdate;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateGlue::Schedule()
+{
+    nsCOMPtr<nsIObserverService> observerService =
+        mozilla::services::GetObserverService();
+    if (observerService) {
+        LOG(("Calling offline-cache-update-added"));
+        observerService->NotifyObservers(static_cast<nsIOfflineCacheUpdate*>(this),
+                                         "offline-cache-update-added",
+                                         nullptr);
+        LOG(("Done offline-cache-update-added"));
+    }
+
+    if (!EnsureUpdate())
+        return NS_ERROR_NULL_POINTER;
+
+    // Do not use weak reference, we must survive!
+    mUpdate->AddObserver(this, false);
+
+    if (mCoalesced) // already scheduled
+        return NS_OK;
+
+    return mUpdate->Schedule();
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateGlue::Init(nsIURI *aManifestURI,
+                             nsIURI *aDocumentURI,
+                             nsIPrincipal* aLoadingPrincipal,
+                             nsIDOMDocument *aDocument,
+                             nsIFile *aCustomProfileDir)
+{
+    nsresult rv;
+
+    nsAutoCString originSuffix;
+    rv = aLoadingPrincipal->GetOriginSuffix(originSuffix);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsOfflineCacheUpdateService* service =
+        nsOfflineCacheUpdateService::EnsureService();
+    if (service) {
+        service->FindUpdate(aManifestURI, originSuffix, aCustomProfileDir,
+                            getter_AddRefs(mUpdate));
+        mCoalesced = !!mUpdate;
+    }
+
+    if (!EnsureUpdate())
+        return NS_ERROR_NULL_POINTER;
+
+    mDocumentURI = aDocumentURI;
+    mLoadingPrincipal = aLoadingPrincipal;
+
+    if (aDocument)
+        SetDocument(aDocument);
+
+    if (mCoalesced) { // already initialized
+        LOG(("OfflineCacheUpdateGlue %p coalesced with update %p", this, mUpdate.get()));
+        return NS_OK;
+    }
+
+    return mUpdate->Init(aManifestURI, aDocumentURI, aLoadingPrincipal, nullptr,
+                         aCustomProfileDir);
+}
+
+void
+OfflineCacheUpdateGlue::SetDocument(nsIDOMDocument *aDocument)
+{
+    // The design is one document for one cache update on the content process.
+    NS_ASSERTION(!mDocument, 
+                 "Setting more then a single document on an instance of OfflineCacheUpdateGlue");
+
+    LOG(("Document %p added to update glue %p", aDocument, this));
+
+    // Add document only if it was not loaded from an offline cache.
+    // If it were loaded from an offline cache then it has already
+    // been associated with it and must not be again cached as
+    // implicit (which are the reasons we collect documents here).
+    nsCOMPtr<nsIDocument> document = do_QueryInterface(aDocument);
+    if (!document)
+        return;
+
+    nsIChannel* channel = document->GetChannel();
+    nsCOMPtr<nsIApplicationCacheChannel> appCacheChannel =
+        do_QueryInterface(channel);
+    if (!appCacheChannel)
+        return;
+
+    bool loadedFromAppCache;
+    appCacheChannel->GetLoadedFromApplicationCache(&loadedFromAppCache);
+    if (loadedFromAppCache)
+        return;
+
+    if (EnsureUpdate()) {
+        mUpdate->StickDocument(mDocumentURI);
+    }
+
+    mDocument = aDocument;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateGlue::UpdateStateChanged(nsIOfflineCacheUpdate *aUpdate, uint32_t state)
+{
+    if (state == nsIOfflineCacheUpdateObserver::STATE_FINISHED) {
+        LOG(("OfflineCacheUpdateGlue got STATE_FINISHED [%p]", this));
+
+        nsCOMPtr<nsIObserverService> observerService =
+          mozilla::services::GetObserverService();
+        if (observerService) {
+            LOG(("Calling offline-cache-update-completed"));
+            observerService->NotifyObservers(static_cast<nsIOfflineCacheUpdate*>(this),
+                                             "offline-cache-update-completed",
+                                             nullptr);
+            LOG(("Done offline-cache-update-completed"));
+        }
+
+        aUpdate->RemoveObserver(this);
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateGlue::ApplicationCacheAvailable(nsIApplicationCache *aApplicationCache)
+{
+    NS_ENSURE_ARG(aApplicationCache);
+
+    // Check that the document that requested this update was
+    // previously associated with an application cache.  If not, it
+    // should be associated with the new one.
+    nsCOMPtr<nsIApplicationCacheContainer> container =
+        do_QueryInterface(mDocument);
+    if (!container)
+        return NS_OK;
+
+    nsCOMPtr<nsIApplicationCache> existingCache;
+    nsresult rv = container->GetApplicationCache(getter_AddRefs(existingCache));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!existingCache) {
+        if (LOG_ENABLED()) {
+            nsAutoCString clientID;
+            if (aApplicationCache) {
+                aApplicationCache->GetClientID(clientID);
+            }
+            LOG(("Update %p: associating app cache %s to document %p",
+                 this, clientID.get(), mDocument.get()));
+        }
+
+        rv = container->SetApplicationCache(aApplicationCache);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    return NS_OK;
+}
+
+} // namespace docshell
+} // namespace mozilla
diff --git a/uriloader/prefetch/OfflineCacheUpdateGlue.h b/uriloader/prefetch/OfflineCacheUpdateGlue.h
new file mode 100644
index 0000000000..92201ec82b
--- /dev/null
+++ b/uriloader/prefetch/OfflineCacheUpdateGlue.h
@@ -0,0 +1,80 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#ifndef nsOfflineCacheUpdateGlue_h
+#define nsOfflineCacheUpdateGlue_h
+
+#include "nsIOfflineCacheUpdate.h"
+
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+#include "nsString.h"
+#include "nsWeakReference.h"
+#include "mozilla/Attributes.h"
+
+class nsOfflineCacheUpdate;
+
+namespace mozilla {
+namespace docshell {
+
+// Like FORWARD_SAFE except methods:
+//    Schedule
+//    Init
+#define NS_ADJUSTED_FORWARD_NSIOFFLINECACHEUPDATE(_to) \
+  NS_IMETHOD GetStatus(uint16_t *aStatus) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetStatus(aStatus); } \
+  NS_IMETHOD GetPartial(bool *aPartial) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetPartial(aPartial); } \
+  NS_IMETHOD GetIsUpgrade(bool *aIsUpgrade) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetIsUpgrade(aIsUpgrade); } \
+  NS_IMETHOD GetUpdateDomain(nsACString & aUpdateDomain) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetUpdateDomain(aUpdateDomain); } \
+  NS_IMETHOD GetManifestURI(nsIURI **aManifestURI) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetManifestURI(aManifestURI); } \
+  NS_IMETHOD GetSucceeded(bool *aSucceeded) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetSucceeded(aSucceeded); } \
+  NS_IMETHOD InitPartial(nsIURI *aManifestURI, const nsACString & aClientID, nsIURI *aDocumentURI, nsIPrincipal *aLoadingPrincipal) override { return !_to ? NS_ERROR_NULL_POINTER : _to->InitPartial(aManifestURI, aClientID, aDocumentURI, aLoadingPrincipal); } \
+  NS_IMETHOD InitForUpdateCheck(nsIURI *aManifestURI, nsIPrincipal* aLoadingPrincipal, nsIObserver *aObserver) override { return !_to ? NS_ERROR_NULL_POINTER : _to->InitForUpdateCheck(aManifestURI, aLoadingPrincipal, aObserver); } \
+  NS_IMETHOD AddDynamicURI(nsIURI *aURI) override { return !_to ? NS_ERROR_NULL_POINTER : _to->AddDynamicURI(aURI); } \
+  NS_IMETHOD AddObserver(nsIOfflineCacheUpdateObserver *aObserver, bool aHoldWeak) override { return !_to ? NS_ERROR_NULL_POINTER : _to->AddObserver(aObserver, aHoldWeak); } \
+  NS_IMETHOD RemoveObserver(nsIOfflineCacheUpdateObserver *aObserver) override { return !_to ? NS_ERROR_NULL_POINTER : _to->RemoveObserver(aObserver); } \
+  NS_IMETHOD GetByteProgress(uint64_t * _result) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetByteProgress(_result); } \
+  NS_IMETHOD Cancel() override { return !_to ? NS_ERROR_NULL_POINTER : _to->Cancel(); }
+
+class OfflineCacheUpdateGlue final : public nsSupportsWeakReference
+                                   , public nsIOfflineCacheUpdate
+                                   , public nsIOfflineCacheUpdateObserver
+{
+public:
+    NS_DECL_ISUPPORTS
+
+private:
+    nsIOfflineCacheUpdate* EnsureUpdate();
+
+public:
+    NS_ADJUSTED_FORWARD_NSIOFFLINECACHEUPDATE(EnsureUpdate())
+    NS_IMETHOD Schedule(void) override;
+    NS_IMETHOD Init(nsIURI *aManifestURI,
+                    nsIURI *aDocumentURI,
+                    nsIPrincipal* aLoadingPrincipal,
+                    nsIDOMDocument *aDocument,
+                    nsIFile *aCustomProfileDir) override;
+
+    NS_DECL_NSIOFFLINECACHEUPDATEOBSERVER
+
+    OfflineCacheUpdateGlue();
+
+    void SetDocument(nsIDOMDocument *aDocument);
+
+private:
+    ~OfflineCacheUpdateGlue();
+
+    RefPtr<nsOfflineCacheUpdate> mUpdate;
+    bool mCoalesced;
+
+    /* Document that requested this update */
+    nsCOMPtr<nsIDOMDocument> mDocument;
+    nsCOMPtr<nsIURI> mDocumentURI;
+    nsCOMPtr<nsIPrincipal> mLoadingPrincipal;
+};
+
+} // namespace docshell
+} // namespace mozilla
+
+#endif
diff --git a/uriloader/prefetch/OfflineCacheUpdateParent.cpp b/uriloader/prefetch/OfflineCacheUpdateParent.cpp
new file mode 100644
index 0000000000..0381ec3f62
--- /dev/null
+++ b/uriloader/prefetch/OfflineCacheUpdateParent.cpp
@@ -0,0 +1,294 @@
+/* -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "OfflineCacheUpdateParent.h"
+
+#include "BackgroundUtils.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/dom/TabParent.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "mozilla/Unused.h"
+#include "nsContentUtils.h"
+#include "nsOfflineCacheUpdate.h"
+#include "nsIApplicationCache.h"
+#include "nsIScriptSecurityManager.h"
+#include "nsNetUtil.h"
+
+using namespace mozilla::ipc;
+using mozilla::BasePrincipal;
+using mozilla::DocShellOriginAttributes;
+using mozilla::PrincipalOriginAttributes;
+using mozilla::dom::TabParent;
+
+//
+// To enable logging (see mozilla/Logging.h for full details):
+//
+//    set MOZ_LOG=nsOfflineCacheUpdate:5
+//    set MOZ_LOG_FILE=offlineupdate.log
+//
+// this enables LogLevel::Debug level information and places all output in
+// the file offlineupdate.log
+//
+extern mozilla::LazyLogModule gOfflineCacheUpdateLog;
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug, args)
+
+#undef LOG_ENABLED
+#define LOG_ENABLED() MOZ_LOG_TEST(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug)
+
+namespace mozilla {
+namespace docshell {
+
+//-----------------------------------------------------------------------------
+// OfflineCacheUpdateParent::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(OfflineCacheUpdateParent,
+                  nsIOfflineCacheUpdateObserver,
+                  nsILoadContext)
+
+//-----------------------------------------------------------------------------
+// OfflineCacheUpdateParent <public>
+//-----------------------------------------------------------------------------
+
+
+OfflineCacheUpdateParent::OfflineCacheUpdateParent()
+    : mIPCClosed(false)
+{
+    // Make sure the service has been initialized
+    nsOfflineCacheUpdateService::EnsureService();
+
+    LOG(("OfflineCacheUpdateParent::OfflineCacheUpdateParent [%p]", this));
+}
+
+OfflineCacheUpdateParent::~OfflineCacheUpdateParent()
+{
+    LOG(("OfflineCacheUpdateParent::~OfflineCacheUpdateParent [%p]", this));
+}
+
+void
+OfflineCacheUpdateParent::ActorDestroy(ActorDestroyReason why)
+{
+    mIPCClosed = true;
+}
+
+nsresult
+OfflineCacheUpdateParent::Schedule(const URIParams& aManifestURI,
+                                   const URIParams& aDocumentURI,
+                                   const PrincipalInfo& aLoadingPrincipalInfo,
+                                   const bool& stickDocument)
+{
+    LOG(("OfflineCacheUpdateParent::RecvSchedule [%p]", this));
+
+    nsresult rv;
+
+    RefPtr<nsOfflineCacheUpdate> update;
+    nsCOMPtr<nsIURI> manifestURI = DeserializeURI(aManifestURI);
+    if (!manifestURI)
+        return NS_ERROR_FAILURE;
+
+    mLoadingPrincipal = PrincipalInfoToPrincipal(aLoadingPrincipalInfo, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsOfflineCacheUpdateService* service =
+        nsOfflineCacheUpdateService::EnsureService();
+    if (!service)
+        return NS_ERROR_FAILURE;
+
+    bool offlinePermissionAllowed = false;
+
+    rv = service->OfflineAppAllowed(
+        mLoadingPrincipal, nullptr, &offlinePermissionAllowed);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!offlinePermissionAllowed)
+        return NS_ERROR_DOM_SECURITY_ERR;
+
+    nsCOMPtr<nsIURI> documentURI = DeserializeURI(aDocumentURI);
+    if (!documentURI)
+        return NS_ERROR_FAILURE;
+
+    if (!NS_SecurityCompareURIs(manifestURI, documentURI, false))
+        return NS_ERROR_DOM_SECURITY_ERR;
+
+    nsAutoCString originSuffix;
+    rv = mLoadingPrincipal->GetOriginSuffix(originSuffix);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    service->FindUpdate(manifestURI,
+                        originSuffix,
+                        nullptr,
+                        getter_AddRefs(update));
+    if (!update) {
+        update = new nsOfflineCacheUpdate();
+
+        // Leave aDocument argument null. Only glues and children keep
+        // document instances.
+        rv = update->Init(manifestURI, documentURI, mLoadingPrincipal, nullptr, nullptr);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        // Must add before Schedule() call otherwise we would miss
+        // oncheck event notification.
+        update->AddObserver(this, false);
+
+        rv = update->Schedule();
+        NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+        update->AddObserver(this, false);
+    }
+
+    if (stickDocument) {
+        nsCOMPtr<nsIURI> stickURI;
+        documentURI->Clone(getter_AddRefs(stickURI));
+        update->StickDocument(stickURI);
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::UpdateStateChanged(nsIOfflineCacheUpdate *aUpdate, uint32_t state)
+{
+    if (mIPCClosed)
+        return NS_ERROR_UNEXPECTED;
+
+    LOG(("OfflineCacheUpdateParent::StateEvent [%p]", this));
+
+    uint64_t byteProgress;
+    aUpdate->GetByteProgress(&byteProgress);
+    Unused << SendNotifyStateEvent(state, byteProgress);
+
+    if (state == nsIOfflineCacheUpdateObserver::STATE_FINISHED) {
+        // Tell the child the particulars after the update has finished.
+        // Sending the Finish event will release the child side of the protocol
+        // and notify "offline-cache-update-completed" on the child process.
+        bool isUpgrade;
+        aUpdate->GetIsUpgrade(&isUpgrade);
+        bool succeeded;
+        aUpdate->GetSucceeded(&succeeded);
+
+        Unused << SendFinish(succeeded, isUpgrade);
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::ApplicationCacheAvailable(nsIApplicationCache *aApplicationCache)
+{
+    if (mIPCClosed)
+        return NS_ERROR_UNEXPECTED;
+
+    NS_ENSURE_ARG(aApplicationCache);
+
+    nsCString cacheClientId;
+    aApplicationCache->GetClientID(cacheClientId);
+    nsCString cacheGroupId;
+    aApplicationCache->GetGroupID(cacheGroupId);
+
+    Unused << SendAssociateDocuments(cacheGroupId, cacheClientId);
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// OfflineCacheUpdateParent::nsILoadContext
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetAssociatedWindow(mozIDOMWindowProxy** aAssociatedWindow)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetTopWindow(mozIDOMWindowProxy** aTopWindow)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetTopFrameElement(nsIDOMElement** aElement)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetNestedFrameId(uint64_t* aId)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetIsContent(bool *aIsContent)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetUsePrivateBrowsing(bool *aUsePrivateBrowsing)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+NS_IMETHODIMP
+OfflineCacheUpdateParent::SetUsePrivateBrowsing(bool aUsePrivateBrowsing)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::SetPrivateBrowsing(bool aUsePrivateBrowsing)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetUseRemoteTabs(bool *aUseRemoteTabs)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::SetRemoteTabs(bool aUseRemoteTabs)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetIsInIsolatedMozBrowserElement(bool *aIsInIsolatedMozBrowserElement)
+{
+    NS_ENSURE_TRUE(mLoadingPrincipal, NS_ERROR_UNEXPECTED);
+    return mLoadingPrincipal->GetIsInIsolatedMozBrowserElement(aIsInIsolatedMozBrowserElement);
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetAppId(uint32_t *aAppId)
+{
+    NS_ENSURE_TRUE(mLoadingPrincipal, NS_ERROR_UNEXPECTED);
+    return mLoadingPrincipal->GetAppId(aAppId);
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::GetOriginAttributes(JS::MutableHandleValue aAttrs)
+{
+    NS_ENSURE_TRUE(mLoadingPrincipal, NS_ERROR_UNEXPECTED);
+
+    JSContext* cx = nsContentUtils::GetCurrentJSContext();
+    MOZ_ASSERT(cx);
+
+    nsresult rv = mLoadingPrincipal->GetOriginAttributes(cx, aAttrs);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+OfflineCacheUpdateParent::IsTrackingProtectionOn(bool* aIsTrackingProtectionOn)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+} // namespace docshell
+} // namespace mozilla
diff --git a/uriloader/prefetch/OfflineCacheUpdateParent.h b/uriloader/prefetch/OfflineCacheUpdateParent.h
new file mode 100644
index 0000000000..f6dbc1cb2a
--- /dev/null
+++ b/uriloader/prefetch/OfflineCacheUpdateParent.h
@@ -0,0 +1,65 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#ifndef nsOfflineCacheUpdateParent_h
+#define nsOfflineCacheUpdateParent_h
+
+#include "mozilla/docshell/POfflineCacheUpdateParent.h"
+#include "mozilla/BasePrincipal.h"
+#include "nsIOfflineCacheUpdate.h"
+
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsILoadContext.h"
+
+class nsIPrincipal;
+
+namespace mozilla {
+
+namespace ipc {
+class URIParams;
+} // namespace ipc
+
+namespace docshell {
+
+class OfflineCacheUpdateParent : public POfflineCacheUpdateParent
+                               , public nsIOfflineCacheUpdateObserver
+                               , public nsILoadContext
+{
+    typedef mozilla::ipc::URIParams URIParams;
+    typedef mozilla::ipc::PrincipalInfo PrincipalInfo;
+
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIOFFLINECACHEUPDATEOBSERVER
+    NS_DECL_NSILOADCONTEXT
+
+    nsresult
+    Schedule(const URIParams& manifestURI,
+             const URIParams& documentURI,
+             const PrincipalInfo& loadingPrincipalInfo,
+             const bool& stickDocument);
+
+    void
+    StopSendingMessagesToChild()
+    {
+      mIPCClosed = true;
+    }
+
+    explicit OfflineCacheUpdateParent();
+
+    virtual void ActorDestroy(ActorDestroyReason aWhy) override;
+private:
+    ~OfflineCacheUpdateParent();
+
+    bool mIPCClosed;
+
+    nsCOMPtr<nsIPrincipal> mLoadingPrincipal;
+};
+
+} // namespace docshell
+} // namespace mozilla
+
+#endif
diff --git a/uriloader/prefetch/POfflineCacheUpdate.ipdl b/uriloader/prefetch/POfflineCacheUpdate.ipdl
new file mode 100644
index 0000000000..e624752522
--- /dev/null
+++ b/uriloader/prefetch/POfflineCacheUpdate.ipdl
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et tw=80 ft=cpp : */
+
+/* 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/. */
+
+include protocol PContent;
+
+namespace mozilla {
+namespace docshell {
+
+//-------------------------------------------------------------------
+protocol POfflineCacheUpdate
+{
+  manager PContent;
+
+parent:
+  async __delete__();
+
+child:
+  async NotifyStateEvent(uint32_t stateEvent, uint64_t byteProgress);
+  async AssociateDocuments(nsCString cacheGroupId, nsCString cacheClientId);
+  async Finish(bool succeeded, bool isUpgrade);
+};
+
+}
+}
diff --git a/uriloader/prefetch/moz.build b/uriloader/prefetch/moz.build
new file mode 100644
index 0000000000..348d57a92c
--- /dev/null
+++ b/uriloader/prefetch/moz.build
@@ -0,0 +1,45 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+XPIDL_SOURCES += [
+    'nsIOfflineCacheUpdate.idl',
+    'nsIPrefetchService.idl',
+]
+
+XPIDL_MODULE = 'prefetch'
+
+EXPORTS += [
+    'nsCPrefetchService.h',
+]
+
+EXPORTS.mozilla.docshell += [
+    'OfflineCacheUpdateChild.h',
+    'OfflineCacheUpdateParent.h',
+]
+
+UNIFIED_SOURCES += [
+    'nsOfflineCacheUpdate.cpp',
+    'nsOfflineCacheUpdateService.cpp',
+    'nsPrefetchService.cpp',
+    'OfflineCacheUpdateChild.cpp',
+    'OfflineCacheUpdateGlue.cpp',
+    'OfflineCacheUpdateParent.cpp',
+]
+
+IPDL_SOURCES += [
+    'POfflineCacheUpdate.ipdl',
+]
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+FINAL_LIBRARY = 'xul'
+
+LOCAL_INCLUDES += [
+    '/dom/base',
+]
+
+if CONFIG['GNU_CXX']:
+    CXXFLAGS += ['-Wno-error=shadow']
diff --git a/uriloader/prefetch/nsCPrefetchService.h b/uriloader/prefetch/nsCPrefetchService.h
new file mode 100644
index 0000000000..d74d89fe7b
--- /dev/null
+++ b/uriloader/prefetch/nsCPrefetchService.h
@@ -0,0 +1,52 @@
+/* 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/. */
+
+#ifndef nsCPrefetchService_h__
+#define nsCPrefetchService_h__
+
+#include "nsIPrefetchService.h"
+
+/**
+ * nsPrefetchService : nsIPrefetchService
+ */
+#define NS_PREFETCHSERVICE_CONTRACTID \
+    "@mozilla.org/prefetch-service;1"
+#define NS_PREFETCHSERVICE_CID                       \
+{ /* 6b8bdffc-3394-417d-be83-a81b7c0f63bf */         \
+    0x6b8bdffc,                                      \
+    0x3394,                                          \
+    0x417d,                                          \
+    {0xbe, 0x83, 0xa8, 0x1b, 0x7c, 0x0f, 0x63, 0xbf} \
+}
+
+/**
+ * nsOfflineCacheUpdateService : nsIOfflineCacheUpdateService
+ */
+
+#define NS_OFFLINECACHEUPDATESERVICE_CONTRACTID \
+  "@mozilla.org/offlinecacheupdate-service;1"
+#define NS_OFFLINECACHEUPDATESERVICE_CID             \
+{ /* ec06f3fc-70db-4ecd-94e0-a6e91ca44d8a */         \
+    0xec06f3fc,                                      \
+    0x70db,                                          \
+    0x4ecd ,                                         \
+    {0x94, 0xe0, 0xa6, 0xe9, 0x1c, 0xa4, 0x4d, 0x8a} \
+}
+
+/**
+ * nsOfflineCacheUpdate : nsIOfflineCacheUpdate
+ */
+
+#define NS_OFFLINECACHEUPDATE_CONTRACTID \
+  "@mozilla.org/offlinecacheupdate;1"
+#define NS_OFFLINECACHEUPDATE_CID                    \
+{ /* e56f5e01-c7cc-4675-a9d7-b8f1e4127295 */         \
+    0xe56f5e01,                                      \
+    0xc7cc,                                          \
+    0x4675,                                          \
+    {0xa9, 0xd7, 0xb8, 0xf1, 0xe4, 0x12, 0x72, 0x95} \
+}
+
+
+#endif // !nsCPrefetchService_h__
diff --git a/uriloader/prefetch/nsIOfflineCacheUpdate.idl b/uriloader/prefetch/nsIOfflineCacheUpdate.idl
new file mode 100644
index 0000000000..1308a8de27
--- /dev/null
+++ b/uriloader/prefetch/nsIOfflineCacheUpdate.idl
@@ -0,0 +1,292 @@
+/* -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "nsISupports.idl"
+
+interface mozIDOMWindow;
+interface nsIURI;
+interface nsIDOMNode;
+interface nsIDOMDocument;
+interface nsIOfflineCacheUpdate;
+interface nsIPrincipal;
+interface nsIPrefBranch;
+interface nsIApplicationCache;
+interface nsIFile;
+interface nsIObserver;
+
+[scriptable, uuid(47360d57-8ef4-4a5d-8865-1a27a739ad1a)]
+interface nsIOfflineCacheUpdateObserver : nsISupports {
+  const unsigned long STATE_ERROR = 1;
+  const unsigned long STATE_CHECKING = 2;
+  const unsigned long STATE_NOUPDATE = 3;
+  const unsigned long STATE_OBSOLETE = 4;
+  const unsigned long STATE_DOWNLOADING = 5;
+  const unsigned long STATE_ITEMSTARTED = 6;
+  const unsigned long STATE_ITEMCOMPLETED = 7;
+  const unsigned long STATE_ITEMPROGRESS = 8;
+  const unsigned long STATE_FINISHED = 10;
+
+  /**
+   * aUpdate has changed its state.
+   *
+   * @param aUpdate
+   *        The nsIOfflineCacheUpdate being processed.
+   * @param event
+   *        See enumeration above
+   */
+  void updateStateChanged(in nsIOfflineCacheUpdate aUpdate, in uint32_t state);
+
+  /**
+   * Informs the observer about an application being available to associate.
+   *
+   * @param applicationCache
+   *        The application cache instance that has been created or found by the 
+   *        update to associate with
+   */
+  void applicationCacheAvailable(in nsIApplicationCache applicationCache);
+};
+
+/**
+ * An nsIOfflineCacheUpdate is used to update an application's offline
+ * resources.
+ *
+ * It can be used to perform partial or complete updates.
+ *
+ * One update object will be updating at a time.  The active object will
+ * load its items one by one, sending itemCompleted() to any registered
+ * observers.
+ */
+[scriptable, uuid(6e3e26ea-45b2-4db7-9e4a-93b965679298)]
+interface nsIOfflineCacheUpdate : nsISupports {
+  /**
+   * Fetch the status of the running update.  This will return a value
+   * defined in nsIDOMOfflineResourceList.
+   */
+  readonly attribute unsigned short status;
+
+  /**
+   * TRUE if the update is being used to add specific resources.
+   * FALSE if the complete cache update process is happening.
+   */
+  readonly attribute boolean partial;
+
+  /**
+   * TRUE if this is an upgrade attempt, FALSE if it is a new cache
+   * attempt.
+   */
+  readonly attribute boolean isUpgrade;
+
+  /**
+   * The domain being updated, and the domain that will own any URIs added
+   * with this update.
+   */
+  readonly attribute ACString updateDomain;
+
+  /**
+   * The manifest for the offline application being updated.
+   */
+  readonly attribute nsIURI manifestURI;
+
+  /**
+   * TRUE if the cache update completed successfully.
+   */
+  readonly attribute boolean succeeded;
+
+  /**
+   * Initialize the update.
+   *
+   * @param aManifestURI
+   *        The manifest URI to be checked.
+   * @param aDocumentURI
+   *        The page that is requesting the update.
+   * @param aLoadingPrincipal
+   *        The principal of the page that is requesting the update.
+   */
+  void init(in nsIURI aManifestURI,
+            in nsIURI aDocumentURI,
+            in nsIPrincipal aLoadingPrincipal,
+            in nsIDOMDocument aDocument,
+            [optional] in nsIFile aCustomProfileDir);
+
+  /**
+   * Initialize the update for partial processing. 
+   *
+   * @param aManifestURI
+   *        The manifest URI of the related cache.
+   * @param aClientID
+   *        Client  ID of the cache to store resource to. This ClientID
+   *        must be ID of cache in the cache group identified by
+   *        the manifest URI passed in the first parameter.
+   * @param aDocumentURI
+   *        The page that is requesting the update. May be null 
+   *        when this information is unknown.
+   */
+  void initPartial(in nsIURI aManifestURI, in ACString aClientID,
+                   in nsIURI aDocumentURI, in nsIPrincipal aPrincipal);
+
+  /**
+   * Initialize the update to only check whether there is an update
+   * to the manifest available (if it has actually changed on the server).
+   *
+   * @param aManifestURI
+   *        The manifest URI of the related cache.
+   * @param aObserver
+   *        nsIObserver implementation that receives the result.
+   *        When aTopic == "offline-cache-update-available" there is an update to
+   *        to download. Update of the app cache will lead to a new version
+   *        download.
+   *        When aTopic == "offline-cache-update-unavailable" then there is no
+   *        update available (the manifest has not changed on the server).
+   */
+  void initForUpdateCheck(in nsIURI aManifestURI,
+                          in nsIPrincipal aLoadingPrincipal,
+                          in nsIObserver aObserver);
+
+  /**
+   * Add a dynamic URI to the offline cache as part of the update.
+   *
+   * @param aURI
+   *        The URI to add.
+   */
+  void addDynamicURI(in nsIURI aURI);
+
+  /**
+   * Add the update to the offline update queue.  An offline-cache-update-added
+   * event will be sent to the observer service.
+   */
+  void schedule();
+
+  /**
+   * Observe loads that are added to the update.
+   *
+   * @param aObserver
+   *        object that notifications will be sent to.
+   * @param aHoldWeak
+   *        TRUE if you want the update to hold a weak reference to the
+   *        observer, FALSE for a strong reference.
+   */
+  void addObserver(in nsIOfflineCacheUpdateObserver aObserver,
+                   in boolean aHoldWeak);
+
+  /**
+   * Remove an observer from the update.
+   *
+   * @param aObserver
+   *        the observer to remove.
+   */
+  void removeObserver(in nsIOfflineCacheUpdateObserver aObserver);
+
+  /**
+   * Cancel the update when still in progress. This stops all running resource
+   * downloads and discards the downloaded cache version. Throws when update
+   * has already finished and made the new cache version active.
+   */
+  void cancel();
+
+  /**
+   * Return the number of bytes downloaded so far
+   */
+  readonly attribute uint64_t byteProgress;
+};
+
+[scriptable, uuid(44971e74-37e4-4140-8677-a4cf213a3f4b)]
+interface nsIOfflineCacheUpdateService : nsISupports {
+    /**
+     * Constants for the offline-app permission.
+     *
+     * XXX: This isn't a great place for this, but it's really the only
+     * private offline-app-related interface
+     */
+
+    /**
+     * Allow the domain to use offline APIs, and don't warn about excessive
+     * usage.
+     */
+    const unsigned long ALLOW_NO_WARN = 3;
+
+    /**
+     * Access to the list of cache updates that have been scheduled.
+     */
+    readonly attribute unsigned long numUpdates;
+    nsIOfflineCacheUpdate getUpdate(in unsigned long index);
+
+    /**
+     * Schedule a cache update for a given offline manifest.  If an
+     * existing update is scheduled or running, that update will be returned.
+     * Otherwise a new update will be scheduled.
+     */
+    nsIOfflineCacheUpdate scheduleUpdate(in nsIURI aManifestURI,
+                                         in nsIURI aDocumentURI,
+                                         in nsIPrincipal aLoadingPrincipal,
+                                         in mozIDOMWindow aWindow);
+
+    /**
+     * Schedule a cache update for a given offline manifest using app cache
+     * bound to the given appID+inIsolatedMozBrowser flag.  If an existing update
+     * is scheduled or running, that update will be returned. Otherwise a new
+     * update will be scheduled.
+     */
+    nsIOfflineCacheUpdate scheduleAppUpdate(in nsIURI aManifestURI,
+                                            in nsIURI aDocumentURI,
+                                            in nsIPrincipal aLoadingPrincipal,
+                                            in nsIFile aProfileDir);
+
+    /**
+     * Schedule a cache update for a manifest when the document finishes
+     * loading.
+     */
+    void scheduleOnDocumentStop(in nsIURI aManifestURI,
+                                in nsIURI aDocumentURI,
+                                in nsIPrincipal aLoadingPrincipal,
+                                in nsIDOMDocument aDocument);
+
+    /**
+     * Schedule a check to see if an update is available.
+     *
+     * This will not update or make any changes to the appcache.
+     * It only notifies the observer to indicate whether the manifest has
+     * changed on the server (or not): a changed manifest means that an
+     * update is available.
+     *
+     * For arguments see nsIOfflineCacheUpdate.initForUpdateCheck() method
+     * description.
+     */
+    void checkForUpdate(in nsIURI aManifestURI,
+                        in nsIPrincipal aLoadingPrincipal,
+                        in nsIObserver aObserver);
+
+    /**
+     * Checks whether a principal should have access to the offline
+     * cache.
+     * @param aPrincipal
+     *        The principal to check.
+     * @param aPrefBranch
+     *        The pref branch to use to check the
+     *        offline-apps.allow_by_default pref.  If not specified,
+     *        the pref service will be used.
+     */
+    boolean offlineAppAllowed(in nsIPrincipal aPrincipal,
+                              in nsIPrefBranch aPrefBranch);
+
+    /**
+     * Checks whether a document at the given URI should have access
+     * to the offline cache.
+     * @param aURI
+     *        The URI to check
+     * @param aPrefBranch
+     *        The pref branch to use to check the
+     *        offline-apps.allow_by_default pref.  If not specified,
+     *        the pref service will be used.
+     */
+    boolean offlineAppAllowedForURI(in nsIURI aURI,
+                                    in nsIPrefBranch aPrefBranch);
+
+    /**
+     * Sets the "offline-app" permission for the principal.
+     * In the single process model calls directly on permission manager.
+     * In the multi process model dispatches to the parent process.
+     */
+    void allowOfflineApp(in nsIPrincipal aPrincipal);
+};
diff --git a/uriloader/prefetch/nsIPrefetchService.idl b/uriloader/prefetch/nsIPrefetchService.idl
new file mode 100644
index 0000000000..198320dd2d
--- /dev/null
+++ b/uriloader/prefetch/nsIPrefetchService.idl
@@ -0,0 +1,37 @@
+/* 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/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface nsIDOMNode;
+interface nsISimpleEnumerator;
+
+[scriptable, uuid(422a1807-4e7f-463d-b8d7-ca2ceb9b5d53)]
+interface nsIPrefetchService : nsISupports
+{
+    /**
+     * Enqueue a request to prefetch the specified URI.
+     *
+     * @param aURI the URI of the document to prefetch
+     * @param aReferrerURI the URI of the referring page
+     * @param aSource the DOM node (such as a <link> tag) that requested this
+     *        fetch, or null if the prefetch was not requested by a DOM node.
+     * @param aExplicit the link element has an explicit prefetch link type
+     */
+    void prefetchURI(in nsIURI aURI,
+                     in nsIURI aReferrerURI,
+                     in nsIDOMNode aSource,
+                     in boolean aExplicit);
+
+    /**
+     * Find out if there are any prefetches running or queued
+     */
+    boolean hasMoreElements();
+
+    /**
+     * Cancel prefetch
+     */
+    void cancelPrefetchURI(in nsIURI aURI, in nsIDOMNode aSource);
+};
diff --git a/uriloader/prefetch/nsOfflineCacheUpdate.cpp b/uriloader/prefetch/nsOfflineCacheUpdate.cpp
new file mode 100644
index 0000000000..4b6cd4d0cf
--- /dev/null
+++ b/uriloader/prefetch/nsOfflineCacheUpdate.cpp
@@ -0,0 +1,2471 @@
+/* -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "nsOfflineCacheUpdate.h"
+
+#include "nsCPrefetchService.h"
+#include "nsCURILoader.h"
+#include "nsIApplicationCacheContainer.h"
+#include "nsIApplicationCacheChannel.h"
+#include "nsIApplicationCacheService.h"
+#include "nsICachingChannel.h"
+#include "nsIContent.h"
+#include "mozilla/dom/Element.h"
+#include "nsIDocumentLoader.h"
+#include "nsIDOMElement.h"
+#include "nsIDOMWindow.h"
+#include "nsIDOMOfflineResourceList.h"
+#include "nsIDocument.h"
+#include "nsIObserverService.h"
+#include "nsIURL.h"
+#include "nsIWebProgress.h"
+#include "nsICryptoHash.h"
+#include "nsICacheEntry.h"
+#include "nsIPermissionManager.h"
+#include "nsIPrincipal.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsServiceManagerUtils.h"
+#include "nsStreamUtils.h"
+#include "nsThreadUtils.h"
+#include "nsProxyRelease.h"
+#include "nsIConsoleService.h"
+#include "mozilla/Logging.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Attributes.h"
+#include "nsContentUtils.h"
+#include "nsIPrincipal.h"
+
+#include "nsXULAppAPI.h"
+
+using namespace mozilla;
+
+static const uint32_t kRescheduleLimit = 3;
+// Max number of retries for every entry of pinned app.
+static const uint32_t kPinnedEntryRetriesLimit = 3;
+// Maximum number of parallel items loads
+static const uint32_t kParallelLoadLimit = 15;
+
+// Quota for offline apps when preloading
+static const int32_t  kCustomProfileQuota = 512000;
+
+//
+// To enable logging (see mozilla/Logging.h for full details):
+//
+//    set MOZ_LOG=nsOfflineCacheUpdate:5
+//    set MOZ_LOG_FILE=offlineupdate.log
+//
+// this enables LogLevel::Debug level information and places all output in
+// the file offlineupdate.log
+//
+extern LazyLogModule gOfflineCacheUpdateLog;
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug, args)
+
+#undef LOG_ENABLED
+#define LOG_ENABLED() MOZ_LOG_TEST(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug)
+
+class AutoFreeArray {
+public:
+    AutoFreeArray(uint32_t count, char **values)
+        : mCount(count), mValues(values) {};
+    ~AutoFreeArray() { NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(mCount, mValues); }
+private:
+    uint32_t mCount;
+    char **mValues;
+};
+
+namespace {
+
+nsresult
+DropReferenceFromURL(nsIURI * aURI)
+{
+    // XXXdholbert If this SetRef fails, callers of this method probably
+    // want to call aURI->CloneIgnoringRef() and use the result of that.
+    return aURI->SetRef(EmptyCString());
+}
+
+void
+LogToConsole(const char * message, nsOfflineCacheUpdateItem * item = nullptr)
+{
+    nsCOMPtr<nsIConsoleService> consoleService =
+        do_GetService(NS_CONSOLESERVICE_CONTRACTID);
+    if (consoleService)
+    {
+        nsAutoString messageUTF16 = NS_ConvertUTF8toUTF16(message);
+        if (item && item->mURI) {
+            messageUTF16.AppendLiteral(", URL=");
+            messageUTF16.Append(
+                NS_ConvertUTF8toUTF16(item->mURI->GetSpecOrDefault()));
+        }
+        consoleService->LogStringMessage(messageUTF16.get());
+    }
+}
+
+} // namespace
+
+//-----------------------------------------------------------------------------
+// nsManifestCheck
+//-----------------------------------------------------------------------------
+
+class nsManifestCheck final : public nsIStreamListener
+                            , public nsIChannelEventSink
+                            , public nsIInterfaceRequestor
+{
+public:
+    nsManifestCheck(nsOfflineCacheUpdate *aUpdate,
+                    nsIURI *aURI,
+                    nsIURI *aReferrerURI,
+                    nsIPrincipal* aLoadingPrincipal)
+        : mUpdate(aUpdate)
+        , mURI(aURI)
+        , mReferrerURI(aReferrerURI)
+        , mLoadingPrincipal(aLoadingPrincipal)
+        {}
+
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIREQUESTOBSERVER
+    NS_DECL_NSISTREAMLISTENER
+    NS_DECL_NSICHANNELEVENTSINK
+    NS_DECL_NSIINTERFACEREQUESTOR
+
+    nsresult Begin();
+
+private:
+
+    ~nsManifestCheck() {}
+
+    static nsresult ReadManifest(nsIInputStream *aInputStream,
+                                 void *aClosure,
+                                 const char *aFromSegment,
+                                 uint32_t aOffset,
+                                 uint32_t aCount,
+                                 uint32_t *aBytesConsumed);
+
+    RefPtr<nsOfflineCacheUpdate> mUpdate;
+    nsCOMPtr<nsIURI> mURI;
+    nsCOMPtr<nsIURI> mReferrerURI;
+    nsCOMPtr<nsIPrincipal> mLoadingPrincipal;
+    nsCOMPtr<nsICryptoHash> mManifestHash;
+    nsCOMPtr<nsIChannel> mChannel;
+};
+
+//-----------------------------------------------------------------------------
+// nsManifestCheck::nsISupports
+//-----------------------------------------------------------------------------
+NS_IMPL_ISUPPORTS(nsManifestCheck,
+                  nsIRequestObserver,
+                  nsIStreamListener,
+                  nsIChannelEventSink,
+                  nsIInterfaceRequestor)
+
+//-----------------------------------------------------------------------------
+// nsManifestCheck <public>
+//-----------------------------------------------------------------------------
+
+nsresult
+nsManifestCheck::Begin()
+{
+    nsresult rv;
+    mManifestHash = do_CreateInstance("@mozilla.org/security/hash;1", &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = mManifestHash->Init(nsICryptoHash::MD5);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = NS_NewChannel(getter_AddRefs(mChannel),
+                       mURI,
+                       mLoadingPrincipal,
+                       nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED,
+                       nsIContentPolicy::TYPE_OTHER,
+                       nullptr,   // loadGroup
+                       nullptr,   // aCallbacks
+                       nsIRequest::LOAD_BYPASS_CACHE);
+
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // configure HTTP specific stuff
+    nsCOMPtr<nsIHttpChannel> httpChannel =
+        do_QueryInterface(mChannel);
+    if (httpChannel) {
+        httpChannel->SetReferrer(mReferrerURI);
+        httpChannel->SetRequestHeader(NS_LITERAL_CSTRING("X-Moz"),
+                                      NS_LITERAL_CSTRING("offline-resource"),
+                                      false);
+    }
+
+    return mChannel->AsyncOpen2(this);
+}
+
+//-----------------------------------------------------------------------------
+// nsManifestCheck <public>
+//-----------------------------------------------------------------------------
+
+/* static */ nsresult
+nsManifestCheck::ReadManifest(nsIInputStream *aInputStream,
+                              void *aClosure,
+                              const char *aFromSegment,
+                              uint32_t aOffset,
+                              uint32_t aCount,
+                              uint32_t *aBytesConsumed)
+{
+    nsManifestCheck *manifestCheck =
+        static_cast<nsManifestCheck*>(aClosure);
+
+    nsresult rv;
+    *aBytesConsumed = aCount;
+
+    rv = manifestCheck->mManifestHash->Update(
+        reinterpret_cast<const uint8_t *>(aFromSegment), aCount);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsManifestCheck::nsIStreamListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsManifestCheck::OnStartRequest(nsIRequest *aRequest,
+                                nsISupports *aContext)
+{
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsManifestCheck::OnDataAvailable(nsIRequest *aRequest,
+                                 nsISupports *aContext,
+                                 nsIInputStream *aStream,
+                                 uint64_t aOffset,
+                                 uint32_t aCount)
+{
+    uint32_t bytesRead;
+    aStream->ReadSegments(ReadManifest, this, aCount, &bytesRead);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsManifestCheck::OnStopRequest(nsIRequest *aRequest,
+                               nsISupports *aContext,
+                               nsresult aStatus)
+{
+    nsAutoCString manifestHash;
+    if (NS_SUCCEEDED(aStatus)) {
+        mManifestHash->Finish(true, manifestHash);
+    }
+
+    mUpdate->ManifestCheckCompleted(aStatus, manifestHash);
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsManifestCheck::nsIInterfaceRequestor
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsManifestCheck::GetInterface(const nsIID &aIID, void **aResult)
+{
+    if (aIID.Equals(NS_GET_IID(nsIChannelEventSink))) {
+        NS_ADDREF_THIS();
+        *aResult = static_cast<nsIChannelEventSink *>(this);
+        return NS_OK;
+    }
+
+    return NS_ERROR_NO_INTERFACE;
+}
+
+//-----------------------------------------------------------------------------
+// nsManifestCheck::nsIChannelEventSink
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsManifestCheck::AsyncOnChannelRedirect(nsIChannel *aOldChannel,
+                                        nsIChannel *aNewChannel,
+                                        uint32_t aFlags,
+                                        nsIAsyncVerifyRedirectCallback *callback)
+{
+    // Redirects should cause the load (and therefore the update) to fail.
+    if (aFlags & nsIChannelEventSink::REDIRECT_INTERNAL) {
+        callback->OnRedirectVerifyCallback(NS_OK);
+        return NS_OK;
+    }
+
+    LogToConsole("Manifest check failed because its response is a redirect");
+
+    aOldChannel->Cancel(NS_ERROR_ABORT);
+    return NS_ERROR_ABORT;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateItem::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsOfflineCacheUpdateItem,
+                  nsIRequestObserver,
+                  nsIStreamListener,
+                  nsIRunnable,
+                  nsIInterfaceRequestor,
+                  nsIChannelEventSink)
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateItem <public>
+//-----------------------------------------------------------------------------
+
+nsOfflineCacheUpdateItem::nsOfflineCacheUpdateItem(nsIURI *aURI,
+                                                   nsIURI *aReferrerURI,
+                                                   nsIPrincipal* aLoadingPrincipal,
+                                                   nsIApplicationCache *aApplicationCache,
+                                                   nsIApplicationCache *aPreviousApplicationCache,
+                                                   uint32_t type,
+                                                   uint32_t loadFlags)
+    : mURI(aURI)
+    , mReferrerURI(aReferrerURI)
+    , mLoadingPrincipal(aLoadingPrincipal)
+    , mApplicationCache(aApplicationCache)
+    , mPreviousApplicationCache(aPreviousApplicationCache)
+    , mItemType(type)
+    , mLoadFlags(loadFlags)
+    , mChannel(nullptr)
+    , mState(LoadStatus::UNINITIALIZED)
+    , mBytesRead(0)
+{
+}
+
+nsOfflineCacheUpdateItem::~nsOfflineCacheUpdateItem()
+{
+}
+
+nsresult
+nsOfflineCacheUpdateItem::OpenChannel(nsOfflineCacheUpdate *aUpdate)
+{
+    if (LOG_ENABLED()) {
+        LOG(("%p: Opening channel for %s", this,
+             mURI->GetSpecOrDefault().get()));
+    }
+
+    if (mUpdate) {
+        // Holding a reference to the update means this item is already
+        // in progress (has a channel, or is just in between OnStopRequest()
+        // and its Run() call.  We must never open channel on this item again.
+        LOG(("  %p is already running! ignoring", this));
+        return NS_ERROR_ALREADY_OPENED;
+    }
+
+    nsresult rv = nsOfflineCacheUpdate::GetCacheKey(mURI, mCacheKey);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    uint32_t flags = nsIRequest::LOAD_BACKGROUND |
+                     nsICachingChannel::LOAD_ONLY_IF_MODIFIED;
+
+    if (mApplicationCache == mPreviousApplicationCache) {
+        // Same app cache to read from and to write to is used during
+        // an only-update-check procedure.  Here we protect the existing
+        // cache from being modified.
+        flags |= nsIRequest::INHIBIT_CACHING;
+    }
+
+    flags |= mLoadFlags;
+
+    rv = NS_NewChannel(getter_AddRefs(mChannel),
+                       mURI,
+                       mLoadingPrincipal,
+                       nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
+                       nsIContentPolicy::TYPE_OTHER,
+                       nullptr,  // aLoadGroup
+                       this,     // aCallbacks
+                       flags);
+
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIApplicationCacheChannel> appCacheChannel =
+        do_QueryInterface(mChannel, &rv);
+
+    // Support for nsIApplicationCacheChannel is required.
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Use the existing application cache as the cache to check.
+    rv = appCacheChannel->SetApplicationCache(mPreviousApplicationCache);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Set the new application cache as the target for write.
+    rv = appCacheChannel->SetApplicationCacheForWrite(mApplicationCache);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // configure HTTP specific stuff
+    nsCOMPtr<nsIHttpChannel> httpChannel =
+        do_QueryInterface(mChannel);
+    if (httpChannel) {
+        httpChannel->SetReferrer(mReferrerURI);
+        httpChannel->SetRequestHeader(NS_LITERAL_CSTRING("X-Moz"),
+                                      NS_LITERAL_CSTRING("offline-resource"),
+                                      false);
+    }
+
+    rv = mChannel->AsyncOpen2(this);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mUpdate = aUpdate;
+
+    mState = LoadStatus::REQUESTED;
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdateItem::Cancel()
+{
+    if (mChannel) {
+        mChannel->Cancel(NS_ERROR_ABORT);
+        mChannel = nullptr;
+    }
+
+    mState = LoadStatus::UNINITIALIZED;
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateItem::nsIStreamListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateItem::OnStartRequest(nsIRequest *aRequest,
+                                         nsISupports *aContext)
+{
+    mState = LoadStatus::RECEIVING;
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateItem::OnDataAvailable(nsIRequest *aRequest,
+                                          nsISupports *aContext,
+                                          nsIInputStream *aStream,
+                                          uint64_t aOffset,
+                                          uint32_t aCount)
+{
+    uint32_t bytesRead = 0;
+    aStream->ReadSegments(NS_DiscardSegment, nullptr, aCount, &bytesRead);
+    mBytesRead += bytesRead;
+    LOG(("loaded %u bytes into offline cache [offset=%llu]\n",
+         bytesRead, aOffset));
+
+    mUpdate->OnByteProgress(bytesRead);
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateItem::OnStopRequest(nsIRequest *aRequest,
+                                        nsISupports *aContext,
+                                        nsresult aStatus)
+{
+    if (LOG_ENABLED()) {
+        LOG(("%p: Done fetching offline item %s [status=%x]\n",
+             this, mURI->GetSpecOrDefault().get(), aStatus));
+    }
+
+    if (mBytesRead == 0 && aStatus == NS_OK) {
+        // we didn't need to read (because LOAD_ONLY_IF_MODIFIED was
+        // specified), but the object should report loadedSize as if it
+        // did.
+        mChannel->GetContentLength(&mBytesRead);
+        mUpdate->OnByteProgress(mBytesRead);
+    }
+
+    if (NS_FAILED(aStatus)) {
+        nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(mChannel);
+        if (httpChannel) {
+            bool isNoStore;
+            if (NS_SUCCEEDED(httpChannel->IsNoStoreResponse(&isNoStore))
+                && isNoStore) {
+                LogToConsole("Offline cache manifest item has Cache-control: no-store header",
+                             this);
+            }
+        }
+    }
+
+    // We need to notify the update that the load is complete, but we
+    // want to give the channel a chance to close the cache entries.
+    NS_DispatchToCurrentThread(this);
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateItem::nsIRunnable
+//-----------------------------------------------------------------------------
+NS_IMETHODIMP
+nsOfflineCacheUpdateItem::Run()
+{
+    // Set mState to LOADED here rather than in OnStopRequest to prevent
+    // race condition when checking state of all mItems in ProcessNextURI().
+    // If state would have been set in OnStopRequest we could mistakenly
+    // take this item as already finished and finish the update process too
+    // early when ProcessNextURI() would get called between OnStopRequest()
+    // and Run() of this item.  Finish() would then have been called twice.
+    mState = LoadStatus::LOADED;
+
+    RefPtr<nsOfflineCacheUpdate> update;
+    update.swap(mUpdate);
+    update->LoadCompleted(this);
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateItem::nsIInterfaceRequestor
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateItem::GetInterface(const nsIID &aIID, void **aResult)
+{
+    if (aIID.Equals(NS_GET_IID(nsIChannelEventSink))) {
+        NS_ADDREF_THIS();
+        *aResult = static_cast<nsIChannelEventSink *>(this);
+        return NS_OK;
+    }
+
+    return NS_ERROR_NO_INTERFACE;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateItem::nsIChannelEventSink
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateItem::AsyncOnChannelRedirect(nsIChannel *aOldChannel,
+                                                 nsIChannel *aNewChannel,
+                                                 uint32_t aFlags,
+                                                 nsIAsyncVerifyRedirectCallback *cb)
+{
+    if (!(aFlags & nsIChannelEventSink::REDIRECT_INTERNAL)) {
+        // Don't allow redirect in case of non-internal redirect and cancel
+        // the channel to clean the cache entry.
+        LogToConsole("Offline cache manifest failed because an item redirects", this);
+
+        aOldChannel->Cancel(NS_ERROR_ABORT);
+        return NS_ERROR_ABORT;
+    }
+
+    nsCOMPtr<nsIURI> newURI;
+    nsresult rv = aNewChannel->GetURI(getter_AddRefs(newURI));
+    if (NS_FAILED(rv))
+        return rv;
+
+    nsCOMPtr<nsIApplicationCacheChannel> appCacheChannel =
+        do_QueryInterface(aNewChannel);
+    if (appCacheChannel) {
+        rv = appCacheChannel->SetApplicationCacheForWrite(mApplicationCache);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    nsAutoCString oldScheme;
+    mURI->GetScheme(oldScheme);
+
+    bool match;
+    if (NS_FAILED(newURI->SchemeIs(oldScheme.get(), &match)) || !match) {
+        LOG(("rejected: redirected to a different scheme\n"));
+        return NS_ERROR_ABORT;
+    }
+
+    // HTTP request headers are not automatically forwarded to the new channel.
+    nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aNewChannel);
+    NS_ENSURE_STATE(httpChannel);
+
+    httpChannel->SetRequestHeader(NS_LITERAL_CSTRING("X-Moz"),
+                                  NS_LITERAL_CSTRING("offline-resource"),
+                                  false);
+
+    mChannel = aNewChannel;
+
+    cb->OnRedirectVerifyCallback(NS_OK);
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdateItem::GetRequestSucceeded(bool * succeeded)
+{
+    *succeeded = false;
+
+    if (!mChannel)
+        return NS_OK;
+
+    nsresult rv;
+    nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(mChannel, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool reqSucceeded;
+    rv = httpChannel->GetRequestSucceeded(&reqSucceeded);
+    if (NS_ERROR_NOT_AVAILABLE == rv)
+        return NS_OK;
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!reqSucceeded) {
+        LOG(("Request failed"));
+        return NS_OK;
+    }
+
+    nsresult channelStatus;
+    rv = httpChannel->GetStatus(&channelStatus);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (NS_FAILED(channelStatus)) {
+        LOG(("Channel status=0x%08x", channelStatus));
+        return NS_OK;
+    }
+
+    *succeeded = true;
+    return NS_OK;
+}
+
+bool
+nsOfflineCacheUpdateItem::IsScheduled()
+{
+    return mState == LoadStatus::UNINITIALIZED;
+}
+
+bool
+nsOfflineCacheUpdateItem::IsInProgress()
+{
+    return mState == LoadStatus::REQUESTED ||
+           mState == LoadStatus::RECEIVING;
+}
+
+bool
+nsOfflineCacheUpdateItem::IsCompleted()
+{
+    return mState == LoadStatus::LOADED;
+}
+
+nsresult
+nsOfflineCacheUpdateItem::GetStatus(uint16_t *aStatus)
+{
+    if (!mChannel) {
+        *aStatus = 0;
+        return NS_OK;
+    }
+
+    nsresult rv;
+    nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(mChannel, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    uint32_t httpStatus;
+    rv = httpChannel->GetResponseStatus(&httpStatus);
+    if (rv == NS_ERROR_NOT_AVAILABLE) {
+        *aStatus = 0;
+        return NS_OK;
+    }
+
+    NS_ENSURE_SUCCESS(rv, rv);
+    *aStatus = uint16_t(httpStatus);
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineManifestItem
+//-----------------------------------------------------------------------------
+
+//-----------------------------------------------------------------------------
+// nsOfflineManifestItem <public>
+//-----------------------------------------------------------------------------
+
+nsOfflineManifestItem::nsOfflineManifestItem(nsIURI *aURI,
+                                             nsIURI *aReferrerURI,
+                                             nsIPrincipal* aLoadingPrincipal,
+                                             nsIApplicationCache *aApplicationCache,
+                                             nsIApplicationCache *aPreviousApplicationCache)
+    : nsOfflineCacheUpdateItem(aURI, aReferrerURI, aLoadingPrincipal,
+                               aApplicationCache, aPreviousApplicationCache,
+                               nsIApplicationCache::ITEM_MANIFEST, 0)
+    , mParserState(PARSE_INIT)
+    , mNeedsUpdate(true)
+    , mStrictFileOriginPolicy(false)
+    , mManifestHashInitialized(false)
+{
+    ReadStrictFileOriginPolicyPref();
+}
+
+nsOfflineManifestItem::~nsOfflineManifestItem()
+{
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineManifestItem <private>
+//-----------------------------------------------------------------------------
+
+/* static */
+nsresult
+nsOfflineManifestItem::ReadManifest(nsIInputStream *aInputStream,
+                                    void *aClosure,
+                                    const char *aFromSegment,
+                                    uint32_t aOffset,
+                                    uint32_t aCount,
+                                    uint32_t *aBytesConsumed)
+{
+    nsOfflineManifestItem *manifest =
+        static_cast<nsOfflineManifestItem*>(aClosure);
+
+    nsresult rv;
+
+    *aBytesConsumed = aCount;
+
+    if (manifest->mParserState == PARSE_ERROR) {
+        // parse already failed, ignore this
+        return NS_OK;
+    }
+
+    if (!manifest->mManifestHashInitialized) {
+        // Avoid re-creation of crypto hash when it fails from some reason the first time
+        manifest->mManifestHashInitialized = true;
+
+        manifest->mManifestHash = do_CreateInstance("@mozilla.org/security/hash;1", &rv);
+        if (NS_SUCCEEDED(rv)) {
+            rv = manifest->mManifestHash->Init(nsICryptoHash::MD5);
+            if (NS_FAILED(rv)) {
+                manifest->mManifestHash = nullptr;
+                LOG(("Could not initialize manifest hash for byte-to-byte check, rv=%08x", rv));
+            }
+        }
+    }
+
+    if (manifest->mManifestHash) {
+        rv = manifest->mManifestHash->Update(reinterpret_cast<const uint8_t *>(aFromSegment), aCount);
+        if (NS_FAILED(rv)) {
+            manifest->mManifestHash = nullptr;
+            LOG(("Could not update manifest hash, rv=%08x", rv));
+        }
+    }
+
+    manifest->mReadBuf.Append(aFromSegment, aCount);
+
+    nsCString::const_iterator begin, iter, end;
+    manifest->mReadBuf.BeginReading(begin);
+    manifest->mReadBuf.EndReading(end);
+
+    for (iter = begin; iter != end; iter++) {
+        if (*iter == '\r' || *iter == '\n') {
+            rv = manifest->HandleManifestLine(begin, iter);
+
+            if (NS_FAILED(rv)) {
+                LOG(("HandleManifestLine failed with 0x%08x", rv));
+                *aBytesConsumed = 0; // Avoid assertion failure in stream tee
+                return NS_ERROR_ABORT;
+            }
+
+            begin = iter;
+            begin++;
+        }
+    }
+
+    // any leftovers are saved for next time
+    manifest->mReadBuf = Substring(begin, end);
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineManifestItem::AddNamespace(uint32_t namespaceType,
+                                    const nsCString &namespaceSpec,
+                                    const nsCString &data)
+
+{
+    nsresult rv;
+    if (!mNamespaces) {
+        mNamespaces = do_CreateInstance(NS_ARRAY_CONTRACTID, &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    nsCOMPtr<nsIApplicationCacheNamespace> ns =
+        do_CreateInstance(NS_APPLICATIONCACHENAMESPACE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = ns->Init(namespaceType, namespaceSpec, data);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = mNamespaces->AppendElement(ns, false);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineManifestItem::HandleManifestLine(const nsCString::const_iterator &aBegin,
+                                          const nsCString::const_iterator &aEnd)
+{
+    nsCString::const_iterator begin = aBegin;
+    nsCString::const_iterator end = aEnd;
+
+    // all lines ignore trailing spaces and tabs
+    nsCString::const_iterator last = end;
+    --last;
+    while (end != begin && (*last == ' ' || *last == '\t')) {
+        --end;
+        --last;
+    }
+
+    if (mParserState == PARSE_INIT) {
+        // Allow a UTF-8 BOM
+        if (begin != end && static_cast<unsigned char>(*begin) == 0xef) {
+            if (++begin == end || static_cast<unsigned char>(*begin) != 0xbb ||
+                ++begin == end || static_cast<unsigned char>(*begin) != 0xbf) {
+                mParserState = PARSE_ERROR;
+                LogToConsole("Offline cache manifest BOM error", this);
+                return NS_OK;
+            }
+            ++begin;
+        }
+
+        const nsCSubstring &magic = Substring(begin, end);
+
+        if (!magic.EqualsLiteral("CACHE MANIFEST")) {
+            mParserState = PARSE_ERROR;
+            LogToConsole("Offline cache manifest magic incorrect", this);
+            return NS_OK;
+        }
+
+        mParserState = PARSE_CACHE_ENTRIES;
+        return NS_OK;
+    }
+
+    // lines other than the first ignore leading spaces and tabs
+    while (begin != end && (*begin == ' ' || *begin == '\t'))
+        begin++;
+
+    // ignore blank lines and comments
+    if (begin == end || *begin == '#')
+        return NS_OK;
+
+    const nsCSubstring &line = Substring(begin, end);
+
+    if (line.EqualsLiteral("CACHE:")) {
+        mParserState = PARSE_CACHE_ENTRIES;
+        return NS_OK;
+    }
+
+    if (line.EqualsLiteral("FALLBACK:")) {
+        mParserState = PARSE_FALLBACK_ENTRIES;
+        return NS_OK;
+    }
+
+    if (line.EqualsLiteral("NETWORK:")) {
+        mParserState = PARSE_BYPASS_ENTRIES;
+        return NS_OK;
+    }
+
+    // Every other section type we don't know must be silently ignored.
+    nsCString::const_iterator lastChar = end;
+    if (*(--lastChar) == ':') {
+        mParserState = PARSE_UNKNOWN_SECTION;
+        return NS_OK;
+    }
+
+    nsresult rv;
+
+    switch(mParserState) {
+    case PARSE_INIT:
+    case PARSE_ERROR: {
+        // this should have been dealt with earlier
+        return NS_ERROR_FAILURE;
+    }
+
+    case PARSE_UNKNOWN_SECTION: {
+        // just jump over
+        return NS_OK;
+    }
+
+    case PARSE_CACHE_ENTRIES: {
+        nsCOMPtr<nsIURI> uri;
+        rv = NS_NewURI(getter_AddRefs(uri), line, nullptr, mURI);
+        if (NS_FAILED(rv))
+            break;
+        if (NS_FAILED(DropReferenceFromURL(uri)))
+            break;
+
+        nsAutoCString scheme;
+        uri->GetScheme(scheme);
+
+        // Manifest URIs must have the same scheme as the manifest.
+        bool match;
+        if (NS_FAILED(mURI->SchemeIs(scheme.get(), &match)) || !match)
+            break;
+
+        mExplicitURIs.AppendObject(uri);
+
+        if (!NS_SecurityCompareURIs(mURI, uri,
+                                    mStrictFileOriginPolicy)) {
+          mAnonymousURIs.AppendObject(uri);
+        }
+
+        break;
+    }
+
+    case PARSE_FALLBACK_ENTRIES: {
+        int32_t separator = line.FindChar(' ');
+        if (separator == kNotFound) {
+            separator = line.FindChar('\t');
+            if (separator == kNotFound)
+                break;
+        }
+
+        nsCString namespaceSpec(Substring(line, 0, separator));
+        nsCString fallbackSpec(Substring(line, separator + 1));
+        namespaceSpec.CompressWhitespace();
+        fallbackSpec.CompressWhitespace();
+
+        nsCOMPtr<nsIURI> namespaceURI;
+        rv = NS_NewURI(getter_AddRefs(namespaceURI), namespaceSpec, nullptr, mURI);
+        if (NS_FAILED(rv))
+            break;
+        if (NS_FAILED(DropReferenceFromURL(namespaceURI)))
+            break;
+        rv = namespaceURI->GetAsciiSpec(namespaceSpec);
+        if (NS_FAILED(rv))
+            break;
+
+        nsCOMPtr<nsIURI> fallbackURI;
+        rv = NS_NewURI(getter_AddRefs(fallbackURI), fallbackSpec, nullptr, mURI);
+        if (NS_FAILED(rv))
+            break;
+        if (NS_FAILED(DropReferenceFromURL(fallbackURI)))
+            break;
+        rv = fallbackURI->GetAsciiSpec(fallbackSpec);
+        if (NS_FAILED(rv))
+            break;
+
+        // Manifest and namespace must be same origin
+        if (!NS_SecurityCompareURIs(mURI, namespaceURI,
+                                    mStrictFileOriginPolicy))
+            break;
+
+        // Fallback and namespace must be same origin
+        if (!NS_SecurityCompareURIs(namespaceURI, fallbackURI,
+                                    mStrictFileOriginPolicy))
+            break;
+
+        mFallbackURIs.AppendObject(fallbackURI);
+
+        AddNamespace(nsIApplicationCacheNamespace::NAMESPACE_FALLBACK,
+                     namespaceSpec, fallbackSpec);
+        break;
+    }
+
+    case PARSE_BYPASS_ENTRIES: {
+        if (line[0] == '*' && (line.Length() == 1 || line[1] == ' ' || line[1] == '\t'))
+        {
+          // '*' indicates to make the online whitelist wildcard flag open,
+          // i.e. do allow load of resources not present in the offline cache
+          // or not conforming any namespace.
+          // We achive that simply by adding an 'empty' - i.e. universal
+          // namespace of BYPASS type into the cache.
+          AddNamespace(nsIApplicationCacheNamespace::NAMESPACE_BYPASS,
+                       EmptyCString(), EmptyCString());
+          break;
+        }
+
+        nsCOMPtr<nsIURI> bypassURI;
+        rv = NS_NewURI(getter_AddRefs(bypassURI), line, nullptr, mURI);
+        if (NS_FAILED(rv))
+            break;
+
+        nsAutoCString scheme;
+        bypassURI->GetScheme(scheme);
+        bool equals;
+        if (NS_FAILED(mURI->SchemeIs(scheme.get(), &equals)) || !equals)
+            break;
+        if (NS_FAILED(DropReferenceFromURL(bypassURI)))
+            break;
+        nsCString spec;
+        if (NS_FAILED(bypassURI->GetAsciiSpec(spec)))
+            break;
+
+        AddNamespace(nsIApplicationCacheNamespace::NAMESPACE_BYPASS,
+                     spec, EmptyCString());
+        break;
+    }
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineManifestItem::GetOldManifestContentHash(nsIRequest *aRequest)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsICachingChannel> cachingChannel = do_QueryInterface(aRequest, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // load the main cache token that is actually the old offline cache token and
+    // read previous manifest content hash value
+    nsCOMPtr<nsISupports> cacheToken;
+    cachingChannel->GetCacheToken(getter_AddRefs(cacheToken));
+    if (cacheToken) {
+        nsCOMPtr<nsICacheEntry> cacheDescriptor(do_QueryInterface(cacheToken, &rv));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        rv = cacheDescriptor->GetMetaDataElement("offline-manifest-hash", getter_Copies(mOldManifestHashValue));
+        if (NS_FAILED(rv))
+            mOldManifestHashValue.Truncate();
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineManifestItem::CheckNewManifestContentHash(nsIRequest *aRequest)
+{
+    nsresult rv;
+
+    if (!mManifestHash) {
+        // Nothing to compare against...
+        return NS_OK;
+    }
+
+    nsCString newManifestHashValue;
+    rv = mManifestHash->Finish(true, mManifestHashValue);
+    mManifestHash = nullptr;
+
+    if (NS_FAILED(rv)) {
+        LOG(("Could not finish manifest hash, rv=%08x", rv));
+        // This is not critical error
+        return NS_OK;
+    }
+
+    if (!ParseSucceeded()) {
+        // Parsing failed, the hash is not valid
+        return NS_OK;
+    }
+
+    if (mOldManifestHashValue == mManifestHashValue) {
+        LOG(("Update not needed, downloaded manifest content is byte-for-byte identical"));
+        mNeedsUpdate = false;
+    }
+
+    // Store the manifest content hash value to the new
+    // offline cache token
+    nsCOMPtr<nsICachingChannel> cachingChannel = do_QueryInterface(aRequest, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsISupports> cacheToken;
+    cachingChannel->GetOfflineCacheToken(getter_AddRefs(cacheToken));
+    if (cacheToken) {
+        nsCOMPtr<nsICacheEntry> cacheDescriptor(do_QueryInterface(cacheToken, &rv));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        rv = cacheDescriptor->SetMetaDataElement("offline-manifest-hash", mManifestHashValue.get());
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    return NS_OK;
+}
+
+void
+nsOfflineManifestItem::ReadStrictFileOriginPolicyPref()
+{
+    mStrictFileOriginPolicy =
+        Preferences::GetBool("security.fileuri.strict_origin_policy", true);
+}
+
+NS_IMETHODIMP
+nsOfflineManifestItem::OnStartRequest(nsIRequest *aRequest,
+                                      nsISupports *aContext)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIHttpChannel> channel = do_QueryInterface(aRequest, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool succeeded;
+    rv = channel->GetRequestSucceeded(&succeeded);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!succeeded) {
+        LOG(("HTTP request failed"));
+        LogToConsole("Offline cache manifest HTTP request failed", this);
+        mParserState = PARSE_ERROR;
+        return NS_ERROR_ABORT;
+    }
+
+    rv = GetOldManifestContentHash(aRequest);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return nsOfflineCacheUpdateItem::OnStartRequest(aRequest, aContext);
+}
+
+NS_IMETHODIMP
+nsOfflineManifestItem::OnDataAvailable(nsIRequest *aRequest,
+                                       nsISupports *aContext,
+                                       nsIInputStream *aStream,
+                                       uint64_t aOffset,
+                                       uint32_t aCount)
+{
+    uint32_t bytesRead = 0;
+    aStream->ReadSegments(ReadManifest, this, aCount, &bytesRead);
+    mBytesRead += bytesRead;
+
+    if (mParserState == PARSE_ERROR) {
+        LOG(("OnDataAvailable is canceling the request due a parse error\n"));
+        return NS_ERROR_ABORT;
+    }
+
+    LOG(("loaded %u bytes into offline cache [offset=%u]\n",
+         bytesRead, aOffset));
+
+    // All the parent method does is read and discard, don't bother
+    // chaining up.
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineManifestItem::OnStopRequest(nsIRequest *aRequest,
+                                     nsISupports *aContext,
+                                     nsresult aStatus)
+{
+    if (mBytesRead == 0) {
+        // We didn't need to read (because LOAD_ONLY_IF_MODIFIED was
+        // specified).
+        mNeedsUpdate = false;
+    } else {
+        // Handle any leftover manifest data.
+        nsCString::const_iterator begin, end;
+        mReadBuf.BeginReading(begin);
+        mReadBuf.EndReading(end);
+        nsresult rv = HandleManifestLine(begin, end);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        rv = CheckNewManifestContentHash(aRequest);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    return nsOfflineCacheUpdateItem::OnStopRequest(aRequest, aContext, aStatus);
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdate::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsOfflineCacheUpdate,
+                  nsIOfflineCacheUpdateObserver,
+                  nsIOfflineCacheUpdate,
+                  nsIRunnable)
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdate <public>
+//-----------------------------------------------------------------------------
+
+nsOfflineCacheUpdate::nsOfflineCacheUpdate()
+    : mState(STATE_UNINITIALIZED)
+    , mAddedItems(false)
+    , mPartialUpdate(false)
+    , mOnlyCheckUpdate(false)
+    , mSucceeded(true)
+    , mObsolete(false)
+    , mItemsInProgress(0)
+    , mRescheduleCount(0)
+    , mPinnedEntryRetriesCount(0)
+    , mPinned(false)
+    , mByteProgress(0)
+{
+}
+
+nsOfflineCacheUpdate::~nsOfflineCacheUpdate()
+{
+    LOG(("nsOfflineCacheUpdate::~nsOfflineCacheUpdate [%p]", this));
+}
+
+/* static */
+nsresult
+nsOfflineCacheUpdate::GetCacheKey(nsIURI *aURI, nsACString &aKey)
+{
+    aKey.Truncate();
+
+    nsCOMPtr<nsIURI> newURI;
+    nsresult rv = aURI->CloneIgnoringRef(getter_AddRefs(newURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = newURI->GetAsciiSpec(aKey);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdate::InitInternal(nsIURI *aManifestURI,
+                                   nsIPrincipal* aLoadingPrincipal)
+{
+    nsresult rv;
+
+    // Only http and https applications are supported.
+    bool match;
+    rv = aManifestURI->SchemeIs("http", &match);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!match) {
+        rv = aManifestURI->SchemeIs("https", &match);
+        NS_ENSURE_SUCCESS(rv, rv);
+        if (!match)
+            return NS_ERROR_ABORT;
+    }
+
+    mManifestURI = aManifestURI;
+    mLoadingPrincipal = aLoadingPrincipal;
+
+    rv = mManifestURI->GetAsciiHost(mUpdateDomain);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mPartialUpdate = false;
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdate::Init(nsIURI *aManifestURI,
+                           nsIURI *aDocumentURI,
+                           nsIPrincipal* aLoadingPrincipal,
+                           nsIDOMDocument *aDocument,
+                           nsIFile *aCustomProfileDir)
+{
+    nsresult rv;
+
+    // Make sure the service has been initialized
+    nsOfflineCacheUpdateService* service =
+        nsOfflineCacheUpdateService::EnsureService();
+    if (!service)
+        return NS_ERROR_FAILURE;
+
+    LOG(("nsOfflineCacheUpdate::Init [%p]", this));
+
+    rv = InitInternal(aManifestURI, aLoadingPrincipal);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIApplicationCacheService> cacheService =
+        do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString originSuffix;
+    rv = aLoadingPrincipal->GetOriginSuffix(originSuffix);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mDocumentURI = aDocumentURI;
+
+    if (aCustomProfileDir) {
+        rv = cacheService->BuildGroupIDForSuffix(aManifestURI, originSuffix, mGroupID);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        // Create only a new offline application cache in the custom profile
+        // This is a preload of a new cache.
+
+        // XXX Custom updates don't support "updating" of an existing cache
+        // in the custom profile at the moment.  This support can be, though,
+        // simply added as well when needed.
+        mPreviousApplicationCache = nullptr;
+
+        rv = cacheService->CreateCustomApplicationCache(mGroupID,
+                                                        aCustomProfileDir,
+                                                        kCustomProfileQuota,
+                                                        getter_AddRefs(mApplicationCache));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        mCustomProfileDir = aCustomProfileDir;
+    }
+    else {
+        rv = cacheService->BuildGroupIDForSuffix(aManifestURI, originSuffix, mGroupID);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        rv = cacheService->GetActiveCache(mGroupID,
+                                          getter_AddRefs(mPreviousApplicationCache));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        rv = cacheService->CreateApplicationCache(mGroupID,
+                                                  getter_AddRefs(mApplicationCache));
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    rv = nsOfflineCacheUpdateService::OfflineAppPinnedForURI(aDocumentURI,
+                                                             nullptr,
+                                                             &mPinned);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mState = STATE_INITIALIZED;
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdate::InitForUpdateCheck(nsIURI *aManifestURI,
+                                         nsIPrincipal* aLoadingPrincipal,
+                                         nsIObserver *aObserver)
+{
+    nsresult rv;
+
+    // Make sure the service has been initialized
+    nsOfflineCacheUpdateService* service =
+        nsOfflineCacheUpdateService::EnsureService();
+    if (!service)
+        return NS_ERROR_FAILURE;
+
+    LOG(("nsOfflineCacheUpdate::InitForUpdateCheck [%p]", this));
+
+    rv = InitInternal(aManifestURI, aLoadingPrincipal);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIApplicationCacheService> cacheService =
+        do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString originSuffix;
+    rv = aLoadingPrincipal->GetOriginSuffix(originSuffix);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = cacheService->BuildGroupIDForSuffix(aManifestURI, originSuffix, mGroupID);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = cacheService->GetActiveCache(mGroupID,
+                                      getter_AddRefs(mPreviousApplicationCache));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // To load the manifest properly using current app cache to satisfy and
+    // also to compare the cached content hash value we have to set 'some'
+    // app cache to write to on the channel.  Otherwise the cached version will
+    // be used and no actual network request will be made.  We use the same
+    // app cache here.  OpenChannel prevents caching in this case using
+    // INHIBIT_CACHING load flag.
+    mApplicationCache = mPreviousApplicationCache;
+
+    rv = nsOfflineCacheUpdateService::OfflineAppPinnedForURI(aManifestURI,
+                                                             nullptr,
+                                                             &mPinned);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mUpdateAvailableObserver = aObserver;
+    mOnlyCheckUpdate = true;
+
+    mState = STATE_INITIALIZED;
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdate::InitPartial(nsIURI *aManifestURI,
+                                  const nsACString& clientID,
+                                  nsIURI *aDocumentURI,
+                                  nsIPrincipal *aLoadingPrincipal)
+{
+    nsresult rv;
+
+    // Make sure the service has been initialized
+    nsOfflineCacheUpdateService* service =
+        nsOfflineCacheUpdateService::EnsureService();
+    if (!service)
+        return NS_ERROR_FAILURE;
+
+    LOG(("nsOfflineCacheUpdate::InitPartial [%p]", this));
+
+    mPartialUpdate = true;
+    mDocumentURI = aDocumentURI;
+    mLoadingPrincipal = aLoadingPrincipal;
+
+    mManifestURI = aManifestURI;
+    rv = mManifestURI->GetAsciiHost(mUpdateDomain);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIApplicationCacheService> cacheService =
+        do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = cacheService->GetApplicationCache(clientID,
+                                           getter_AddRefs(mApplicationCache));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!mApplicationCache) {
+        nsAutoCString manifestSpec;
+        rv = GetCacheKey(mManifestURI, manifestSpec);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        rv = cacheService->CreateApplicationCache
+            (manifestSpec, getter_AddRefs(mApplicationCache));
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    rv = mApplicationCache->GetManifestURI(getter_AddRefs(mManifestURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString groupID;
+    rv = mApplicationCache->GetGroupID(groupID);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = nsOfflineCacheUpdateService::OfflineAppPinnedForURI(aDocumentURI,
+                                                             nullptr,
+                                                             &mPinned);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mState = STATE_INITIALIZED;
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdate::HandleManifest(bool *aDoUpdate)
+{
+    // Be pessimistic
+    *aDoUpdate = false;
+
+    bool succeeded;
+    nsresult rv = mManifestItem->GetRequestSucceeded(&succeeded);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!succeeded || !mManifestItem->ParseSucceeded()) {
+        return NS_ERROR_FAILURE;
+    }
+
+    if (!mManifestItem->NeedsUpdate()) {
+        return NS_OK;
+    }
+
+    // Add items requested by the manifest.
+    const nsCOMArray<nsIURI> &manifestURIs = mManifestItem->GetExplicitURIs();
+    for (int32_t i = 0; i < manifestURIs.Count(); i++) {
+        rv = AddURI(manifestURIs[i], nsIApplicationCache::ITEM_EXPLICIT);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    const nsCOMArray<nsIURI> &anonURIs = mManifestItem->GetAnonymousURIs();
+    for (int32_t i = 0; i < anonURIs.Count(); i++) {
+      rv = AddURI(anonURIs[i], nsIApplicationCache::ITEM_EXPLICIT,
+                  nsIRequest::LOAD_ANONYMOUS);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    const nsCOMArray<nsIURI> &fallbackURIs = mManifestItem->GetFallbackURIs();
+    for (int32_t i = 0; i < fallbackURIs.Count(); i++) {
+        rv = AddURI(fallbackURIs[i], nsIApplicationCache::ITEM_FALLBACK);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // The document that requested the manifest is implicitly included
+    // as part of that manifest update.
+    rv = AddURI(mDocumentURI, nsIApplicationCache::ITEM_IMPLICIT);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Add items previously cached implicitly
+    rv = AddExistingItems(nsIApplicationCache::ITEM_IMPLICIT);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Add items requested by the script API
+    rv = AddExistingItems(nsIApplicationCache::ITEM_DYNAMIC);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Add opportunistically cached items conforming current opportunistic
+    // namespace list
+    rv = AddExistingItems(nsIApplicationCache::ITEM_OPPORTUNISTIC,
+                          &mManifestItem->GetOpportunisticNamespaces());
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    *aDoUpdate = true;
+
+    return NS_OK;
+}
+
+bool
+nsOfflineCacheUpdate::CheckUpdateAvailability()
+{
+    nsresult rv;
+
+    bool succeeded;
+    rv = mManifestItem->GetRequestSucceeded(&succeeded);
+    NS_ENSURE_SUCCESS(rv, false);
+
+    if (!succeeded || !mManifestItem->ParseSucceeded()) {
+        return false;
+    }
+
+    if (!mPinned) {
+        uint16_t status;
+        rv = mManifestItem->GetStatus(&status);
+        NS_ENSURE_SUCCESS(rv, false);
+
+        // Treat these as there would be an update available,
+        // since this is indication of demand to remove this
+        // offline cache.
+        if (status == 404 || status == 410) {
+            return true;
+        }
+    }
+
+    return mManifestItem->NeedsUpdate();
+}
+
+void
+nsOfflineCacheUpdate::LoadCompleted(nsOfflineCacheUpdateItem *aItem)
+{
+    nsresult rv;
+
+    LOG(("nsOfflineCacheUpdate::LoadCompleted [%p]", this));
+
+    if (mState == STATE_FINISHED) {
+        LOG(("  after completion, ignoring"));
+        return;
+    }
+
+    // Keep the object alive through a Finish() call.
+    nsCOMPtr<nsIOfflineCacheUpdate> kungFuDeathGrip(this);
+
+    if (mState == STATE_CANCELLED) {
+        NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+        Finish();
+        return;
+    }
+
+    if (mState == STATE_CHECKING) {
+        // Manifest load finished.
+
+        if (mOnlyCheckUpdate) {
+            Finish();
+            NotifyUpdateAvailability(CheckUpdateAvailability());
+            return;
+        }
+
+        NS_ASSERTION(mManifestItem,
+                     "Must have a manifest item in STATE_CHECKING.");
+        NS_ASSERTION(mManifestItem == aItem,
+                     "Unexpected aItem in nsOfflineCacheUpdate::LoadCompleted");
+
+        // A 404 or 410 is interpreted as an intentional removal of
+        // the manifest file, rather than a transient server error.
+        // Obsolete this cache group if one of these is returned.
+        uint16_t status;
+        rv = mManifestItem->GetStatus(&status);
+        if (status == 404 || status == 410) {
+            LogToConsole("Offline cache manifest removed, cache cleared", mManifestItem);
+            mSucceeded = false;
+            if (mPreviousApplicationCache) {
+                if (mPinned) {
+                    // Do not obsolete a pinned application.
+                    NotifyState(nsIOfflineCacheUpdateObserver::STATE_NOUPDATE);
+                } else {
+                    NotifyState(nsIOfflineCacheUpdateObserver::STATE_OBSOLETE);
+                    mObsolete = true;
+                }
+            } else {
+                NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+                mObsolete = true;
+            }
+            Finish();
+            return;
+        }
+
+        bool doUpdate;
+        if (NS_FAILED(HandleManifest(&doUpdate))) {
+            mSucceeded = false;
+            NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+            Finish();
+            return;
+        }
+
+        if (!doUpdate) {
+            LogToConsole("Offline cache doesn't need to update", mManifestItem);
+
+            mSucceeded = false;
+
+            AssociateDocuments(mPreviousApplicationCache);
+
+            ScheduleImplicit();
+
+            // If we didn't need an implicit update, we can
+            // send noupdate and end the update now.
+            if (!mImplicitUpdate) {
+                NotifyState(nsIOfflineCacheUpdateObserver::STATE_NOUPDATE);
+                Finish();
+            }
+            return;
+        }
+
+        rv = mApplicationCache->MarkEntry(mManifestItem->mCacheKey,
+                                          mManifestItem->mItemType);
+        if (NS_FAILED(rv)) {
+            mSucceeded = false;
+            NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+            Finish();
+            return;
+        }
+
+        mState = STATE_DOWNLOADING;
+        NotifyState(nsIOfflineCacheUpdateObserver::STATE_DOWNLOADING);
+
+        // Start fetching resources.
+        ProcessNextURI();
+
+        return;
+    }
+
+    // Normal load finished.
+    if (mItemsInProgress) // Just to be safe here!
+      --mItemsInProgress;
+
+    bool succeeded;
+    rv = aItem->GetRequestSucceeded(&succeeded);
+
+    if (mPinned && NS_SUCCEEDED(rv) && succeeded) {
+        uint32_t dummy_cache_type;
+        rv = mApplicationCache->GetTypes(aItem->mCacheKey, &dummy_cache_type);
+        bool item_doomed = NS_FAILED(rv); // can not find it? -> doomed
+
+        if (item_doomed &&
+            mPinnedEntryRetriesCount < kPinnedEntryRetriesLimit &&
+            (aItem->mItemType & (nsIApplicationCache::ITEM_EXPLICIT |
+                                 nsIApplicationCache::ITEM_FALLBACK))) {
+            rv = EvictOneNonPinned();
+            if (NS_FAILED(rv)) {
+                mSucceeded = false;
+                NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+                Finish();
+                return;
+            }
+
+            // This reverts the item state to UNINITIALIZED that makes it to
+            // be scheduled for download again.
+            rv = aItem->Cancel();
+            if (NS_FAILED(rv)) {
+                mSucceeded = false;
+                NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+                Finish();
+                return;
+            }
+
+            mPinnedEntryRetriesCount++;
+
+            LogToConsole("An unpinned offline cache deleted");
+
+            // Retry this item.
+            ProcessNextURI();
+            return;
+        }
+    }
+
+    // According to parallelism this may imply more pinned retries count,
+    // but that is not critical, since at one moment the algoritm will
+    // stop anyway.  Also, this code may soon be completely removed
+    // after we have a separate storage for pinned apps.
+    mPinnedEntryRetriesCount = 0;
+
+    // Check for failures.  3XX, 4XX and 5XX errors on items explicitly
+    // listed in the manifest will cause the update to fail.
+    if (NS_FAILED(rv) || !succeeded) {
+        if (aItem->mItemType &
+            (nsIApplicationCache::ITEM_EXPLICIT |
+             nsIApplicationCache::ITEM_FALLBACK)) {
+            LogToConsole("Offline cache manifest item failed to load", aItem);
+            mSucceeded = false;
+        }
+    } else {
+        rv = mApplicationCache->MarkEntry(aItem->mCacheKey, aItem->mItemType);
+        if (NS_FAILED(rv)) {
+            mSucceeded = false;
+        }
+    }
+
+    if (!mSucceeded) {
+        NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+        Finish();
+        return;
+    }
+
+    NotifyState(nsIOfflineCacheUpdateObserver::STATE_ITEMCOMPLETED);
+
+    ProcessNextURI();
+}
+
+void
+nsOfflineCacheUpdate::ManifestCheckCompleted(nsresult aStatus,
+                                             const nsCString &aManifestHash)
+{
+    // Keep the object alive through a Finish() call.
+    nsCOMPtr<nsIOfflineCacheUpdate> kungFuDeathGrip(this);
+
+    if (NS_SUCCEEDED(aStatus)) {
+        nsAutoCString firstManifestHash;
+        mManifestItem->GetManifestHash(firstManifestHash);
+        if (aManifestHash != firstManifestHash) {
+            LOG(("Manifest has changed during cache items download [%p]", this));
+            LogToConsole("Offline cache manifest changed during update", mManifestItem);
+            aStatus = NS_ERROR_FAILURE;
+        }
+    }
+
+    if (NS_FAILED(aStatus)) {
+        mSucceeded = false;
+        NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+    }
+
+    if (NS_FAILED(aStatus) && mRescheduleCount < kRescheduleLimit) {
+        // Do the final stuff but prevent notification of STATE_FINISHED.
+        // That would disconnect listeners that are responsible for document
+        // association after a successful update. Forwarding notifications
+        // from a new update through this dead update to them is absolutely
+        // correct.
+        FinishNoNotify();
+
+        RefPtr<nsOfflineCacheUpdate> newUpdate =
+            new nsOfflineCacheUpdate();
+        // Leave aDocument argument null. Only glues and children keep
+        // document instances.
+        newUpdate->Init(mManifestURI, mDocumentURI, mLoadingPrincipal, nullptr,
+                        mCustomProfileDir);
+
+        // In a rare case the manifest will not be modified on the next refetch
+        // transfer all master document URIs to the new update to ensure that
+        // all documents refering it will be properly cached.
+        for (int32_t i = 0; i < mDocumentURIs.Count(); i++) {
+            newUpdate->StickDocument(mDocumentURIs[i]);
+        }
+
+        newUpdate->mRescheduleCount = mRescheduleCount + 1;
+        newUpdate->AddObserver(this, false);
+        newUpdate->Schedule();
+    }
+    else {
+        LogToConsole("Offline cache update done", mManifestItem);
+        Finish();
+    }
+}
+
+nsresult
+nsOfflineCacheUpdate::Begin()
+{
+    LOG(("nsOfflineCacheUpdate::Begin [%p]", this));
+
+    // Keep the object alive through a ProcessNextURI()/Finish() call.
+    nsCOMPtr<nsIOfflineCacheUpdate> kungFuDeathGrip(this);
+
+    mItemsInProgress = 0;
+
+    if (mState == STATE_CANCELLED) {
+      nsresult rv = NS_DispatchToMainThread(NewRunnableMethod(this,
+                                                              &nsOfflineCacheUpdate::AsyncFinishWithError));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      return NS_OK;
+    }
+
+    if (mPartialUpdate) {
+        mState = STATE_DOWNLOADING;
+        NotifyState(nsIOfflineCacheUpdateObserver::STATE_DOWNLOADING);
+        ProcessNextURI();
+        return NS_OK;
+    }
+
+    // Start checking the manifest.
+    mManifestItem = new nsOfflineManifestItem(mManifestURI,
+                                              mDocumentURI,
+                                              mLoadingPrincipal,
+                                              mApplicationCache,
+                                              mPreviousApplicationCache);
+    if (!mManifestItem) {
+        return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    mState = STATE_CHECKING;
+    mByteProgress = 0;
+    NotifyState(nsIOfflineCacheUpdateObserver::STATE_CHECKING);
+
+    nsresult rv = mManifestItem->OpenChannel(this);
+    if (NS_FAILED(rv)) {
+        LoadCompleted(mManifestItem);
+    }
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdate <private>
+//-----------------------------------------------------------------------------
+
+nsresult
+nsOfflineCacheUpdate::AddExistingItems(uint32_t aType,
+                                       nsTArray<nsCString>* namespaceFilter)
+{
+    if (!mPreviousApplicationCache) {
+        return NS_OK;
+    }
+
+    if (namespaceFilter && namespaceFilter->Length() == 0) {
+        // Don't bother to walk entries when there are no namespaces
+        // defined.
+        return NS_OK;
+    }
+
+    uint32_t count = 0;
+    char **keys = nullptr;
+    nsresult rv = mPreviousApplicationCache->GatherEntries(aType,
+                                                           &count, &keys);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    AutoFreeArray autoFree(count, keys);
+
+    for (uint32_t i = 0; i < count; i++) {
+        if (namespaceFilter) {
+            bool found = false;
+            for (uint32_t j = 0; j < namespaceFilter->Length() && !found; j++) {
+                found = StringBeginsWith(nsDependentCString(keys[i]),
+                                         namespaceFilter->ElementAt(j));
+            }
+
+            if (!found)
+                continue;
+        }
+
+        nsCOMPtr<nsIURI> uri;
+        if (NS_SUCCEEDED(NS_NewURI(getter_AddRefs(uri), keys[i]))) {
+            rv = AddURI(uri, aType);
+            NS_ENSURE_SUCCESS(rv, rv);
+        }
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdate::ProcessNextURI()
+{
+    // Keep the object alive through a Finish() call.
+    nsCOMPtr<nsIOfflineCacheUpdate> kungFuDeathGrip(this);
+
+    LOG(("nsOfflineCacheUpdate::ProcessNextURI [%p, inprogress=%d, numItems=%d]",
+         this, mItemsInProgress, mItems.Length()));
+
+    if (mState != STATE_DOWNLOADING) {
+        LOG(("  should only be called from the DOWNLOADING state, ignoring"));
+        return NS_ERROR_UNEXPECTED;
+    }
+
+    nsOfflineCacheUpdateItem * runItem = nullptr;
+    uint32_t completedItems = 0;
+    for (uint32_t i = 0; i < mItems.Length(); ++i) {
+        nsOfflineCacheUpdateItem * item = mItems[i];
+
+        if (item->IsScheduled()) {
+            runItem = item;
+            break;
+        }
+
+        if (item->IsCompleted())
+            ++completedItems;
+    }
+
+    if (completedItems == mItems.Length()) {
+        LOG(("nsOfflineCacheUpdate::ProcessNextURI [%p]: all items loaded", this));
+
+        if (mPartialUpdate) {
+            return Finish();
+        } else {
+            // Verify that the manifest wasn't changed during the
+            // update, to prevent capturing a cache while the server
+            // is being updated.  The check will call
+            // ManifestCheckCompleted() when it's done.
+            RefPtr<nsManifestCheck> manifestCheck =
+                new nsManifestCheck(this, mManifestURI, mDocumentURI, mLoadingPrincipal);
+            if (NS_FAILED(manifestCheck->Begin())) {
+                mSucceeded = false;
+                NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+                return Finish();
+            }
+
+            return NS_OK;
+        }
+    }
+
+    if (!runItem) {
+        LOG(("nsOfflineCacheUpdate::ProcessNextURI [%p]:"
+             " No more items to include in parallel load", this));
+        return NS_OK;
+    }
+
+    if (LOG_ENABLED()) {
+        LOG(("%p: Opening channel for %s", this,
+             runItem->mURI->GetSpecOrDefault().get()));
+    }
+
+    ++mItemsInProgress;
+    NotifyState(nsIOfflineCacheUpdateObserver::STATE_ITEMSTARTED);
+
+    nsresult rv = runItem->OpenChannel(this);
+    if (NS_FAILED(rv)) {
+        LoadCompleted(runItem);
+        return rv;
+    }
+
+    if (mItemsInProgress >= kParallelLoadLimit) {
+        LOG(("nsOfflineCacheUpdate::ProcessNextURI [%p]:"
+             " At parallel load limit", this));
+        return NS_OK;
+    }
+
+    // This calls this method again via a post triggering
+    // a parallel item load
+    return NS_DispatchToCurrentThread(this);
+}
+
+void
+nsOfflineCacheUpdate::GatherObservers(nsCOMArray<nsIOfflineCacheUpdateObserver> &aObservers)
+{
+    for (int32_t i = 0; i < mWeakObservers.Count(); i++) {
+        nsCOMPtr<nsIOfflineCacheUpdateObserver> observer =
+            do_QueryReferent(mWeakObservers[i]);
+        if (observer)
+            aObservers.AppendObject(observer);
+        else
+            mWeakObservers.RemoveObjectAt(i--);
+    }
+
+    for (int32_t i = 0; i < mObservers.Count(); i++) {
+        aObservers.AppendObject(mObservers[i]);
+    }
+}
+
+void
+nsOfflineCacheUpdate::NotifyState(uint32_t state)
+{
+    LOG(("nsOfflineCacheUpdate::NotifyState [%p, %d]", this, state));
+
+    if (state == STATE_ERROR) {
+        LogToConsole("Offline cache update error", mManifestItem);
+    }
+
+    nsCOMArray<nsIOfflineCacheUpdateObserver> observers;
+    GatherObservers(observers);
+
+    for (int32_t i = 0; i < observers.Count(); i++) {
+        observers[i]->UpdateStateChanged(this, state);
+    }
+}
+
+void
+nsOfflineCacheUpdate::NotifyUpdateAvailability(bool updateAvailable)
+{
+    if (!mUpdateAvailableObserver)
+        return;
+
+    LOG(("nsOfflineCacheUpdate::NotifyUpdateAvailability [this=%p, avail=%d]",
+         this, updateAvailable));
+
+    const char* topic = updateAvailable
+                      ? "offline-cache-update-available"
+                      : "offline-cache-update-unavailable";
+
+    nsCOMPtr<nsIObserver> observer;
+    observer.swap(mUpdateAvailableObserver);
+    observer->Observe(mManifestURI, topic, nullptr);
+}
+
+void
+nsOfflineCacheUpdate::AssociateDocuments(nsIApplicationCache* cache)
+{
+    if (!cache) {
+        LOG(("nsOfflineCacheUpdate::AssociateDocuments bypassed"
+             ", no cache provided [this=%p]", this));
+        return;
+    }
+
+    nsCOMArray<nsIOfflineCacheUpdateObserver> observers;
+    GatherObservers(observers);
+
+    for (int32_t i = 0; i < observers.Count(); i++) {
+        observers[i]->ApplicationCacheAvailable(cache);
+    }
+}
+
+void
+nsOfflineCacheUpdate::StickDocument(nsIURI *aDocumentURI)
+{
+    if (!aDocumentURI)
+      return;
+
+    mDocumentURIs.AppendObject(aDocumentURI);
+}
+
+void
+nsOfflineCacheUpdate::SetOwner(nsOfflineCacheUpdateOwner *aOwner)
+{
+    NS_ASSERTION(!mOwner, "Tried to set cache update owner twice.");
+    mOwner = aOwner;
+}
+
+bool
+nsOfflineCacheUpdate::IsForGroupID(const nsCSubstring &groupID)
+{
+    return mGroupID == groupID;
+}
+
+bool
+nsOfflineCacheUpdate::IsForProfile(nsIFile* aCustomProfileDir)
+{
+    if (!mCustomProfileDir && !aCustomProfileDir)
+        return true;
+    if (!mCustomProfileDir || !aCustomProfileDir)
+        return false;
+
+    bool equals;
+    nsresult rv = mCustomProfileDir->Equals(aCustomProfileDir, &equals);
+
+    return NS_SUCCEEDED(rv) && equals;
+}
+
+nsresult
+nsOfflineCacheUpdate::UpdateFinished(nsOfflineCacheUpdate *aUpdate)
+{
+    // Keep the object alive through a Finish() call.
+    nsCOMPtr<nsIOfflineCacheUpdate> kungFuDeathGrip(this);
+
+    mImplicitUpdate = nullptr;
+
+    NotifyState(nsIOfflineCacheUpdateObserver::STATE_NOUPDATE);
+    Finish();
+
+    return NS_OK;
+}
+
+void
+nsOfflineCacheUpdate::OnByteProgress(uint64_t byteIncrement)
+{
+    mByteProgress += byteIncrement;
+    NotifyState(nsIOfflineCacheUpdateObserver::STATE_ITEMPROGRESS);
+}
+
+nsresult
+nsOfflineCacheUpdate::ScheduleImplicit()
+{
+    if (mDocumentURIs.Count() == 0)
+        return NS_OK;
+
+    nsresult rv;
+
+    RefPtr<nsOfflineCacheUpdate> update = new nsOfflineCacheUpdate();
+    NS_ENSURE_TRUE(update, NS_ERROR_OUT_OF_MEMORY);
+
+    nsAutoCString clientID;
+    if (mPreviousApplicationCache) {
+        rv = mPreviousApplicationCache->GetClientID(clientID);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+    else if (mApplicationCache) {
+        rv = mApplicationCache->GetClientID(clientID);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+    else {
+        NS_ERROR("Offline cache update not having set mApplicationCache?");
+    }
+
+    rv = update->InitPartial(mManifestURI, clientID, mDocumentURI, mLoadingPrincipal);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    for (int32_t i = 0; i < mDocumentURIs.Count(); i++) {
+        rv = update->AddURI(mDocumentURIs[i],
+              nsIApplicationCache::ITEM_IMPLICIT);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    update->SetOwner(this);
+    rv = update->Begin();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mImplicitUpdate = update;
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdate::FinishNoNotify()
+{
+    LOG(("nsOfflineCacheUpdate::Finish [%p]", this));
+
+    mState = STATE_FINISHED;
+
+    if (!mPartialUpdate && !mOnlyCheckUpdate) {
+        if (mSucceeded) {
+            nsIArray *namespaces = mManifestItem->GetNamespaces();
+            nsresult rv = mApplicationCache->AddNamespaces(namespaces);
+            if (NS_FAILED(rv)) {
+                NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+                mSucceeded = false;
+            }
+
+            rv = mApplicationCache->Activate();
+            if (NS_FAILED(rv)) {
+                NotifyState(nsIOfflineCacheUpdateObserver::STATE_ERROR);
+                mSucceeded = false;
+            }
+
+            AssociateDocuments(mApplicationCache);
+        }
+
+        if (mObsolete) {
+            nsCOMPtr<nsIApplicationCacheService> appCacheService =
+                do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID);
+            if (appCacheService) {
+                nsAutoCString groupID;
+                mApplicationCache->GetGroupID(groupID);
+                appCacheService->DeactivateGroup(groupID);
+             }
+        }
+
+        if (!mSucceeded) {
+            // Update was not merged, mark all the loads as failures
+            for (uint32_t i = 0; i < mItems.Length(); i++) {
+                mItems[i]->Cancel();
+            }
+
+            mApplicationCache->Discard();
+        }
+    }
+
+    nsresult rv = NS_OK;
+
+    if (mOwner) {
+        rv = mOwner->UpdateFinished(this);
+        // mozilla::WeakPtr is missing some key features, like setting it to
+        // null explicitly.
+        mOwner = mozilla::WeakPtr<nsOfflineCacheUpdateOwner>();
+    }
+
+    return rv;
+}
+
+nsresult
+nsOfflineCacheUpdate::Finish()
+{
+    nsresult rv = FinishNoNotify();
+
+    NotifyState(nsIOfflineCacheUpdateObserver::STATE_FINISHED);
+
+    return rv;
+}
+
+void
+nsOfflineCacheUpdate::AsyncFinishWithError()
+{
+    NotifyState(nsOfflineCacheUpdate::STATE_ERROR);
+    Finish();
+}
+
+static nsresult
+EvictOneOfCacheGroups(nsIApplicationCacheService *cacheService,
+                      uint32_t count, const char * const *groups)
+{
+    nsresult rv;
+    unsigned int i;
+
+    for (i = 0; i < count; i++) {
+        nsCOMPtr<nsIURI> uri;
+        rv = NS_NewURI(getter_AddRefs(uri), groups[i]);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        nsDependentCString group_name(groups[i]);
+        nsCOMPtr<nsIApplicationCache> cache;
+        rv = cacheService->GetActiveCache(group_name, getter_AddRefs(cache));
+        // Maybe someone in another thread or process have deleted it.
+        if (NS_FAILED(rv) || !cache)
+            continue;
+
+        bool pinned;
+        rv = nsOfflineCacheUpdateService::OfflineAppPinnedForURI(uri,
+                                                                 nullptr,
+                                                                 &pinned);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        if (!pinned) {
+            rv = cache->Discard();
+            return NS_OK;
+        }
+    }
+
+    return NS_ERROR_FILE_NOT_FOUND;
+}
+
+nsresult
+nsOfflineCacheUpdate::EvictOneNonPinned()
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIApplicationCacheService> cacheService =
+        do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    uint32_t count;
+    char **groups;
+    rv = cacheService->GetGroupsTimeOrdered(&count, &groups);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = EvictOneOfCacheGroups(cacheService, count, groups);
+
+    NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(count, groups);
+    return rv;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdate::nsIOfflineCacheUpdate
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::GetUpdateDomain(nsACString &aUpdateDomain)
+{
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    aUpdateDomain = mUpdateDomain;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::GetStatus(uint16_t *aStatus)
+{
+    switch (mState) {
+    case STATE_CHECKING :
+        *aStatus = nsIDOMOfflineResourceList::CHECKING;
+        return NS_OK;
+    case STATE_DOWNLOADING :
+        *aStatus = nsIDOMOfflineResourceList::DOWNLOADING;
+        return NS_OK;
+    default :
+        *aStatus = nsIDOMOfflineResourceList::IDLE;
+        return NS_OK;
+    }
+
+    return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::GetPartial(bool *aPartial)
+{
+    *aPartial = mPartialUpdate || mOnlyCheckUpdate;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::GetManifestURI(nsIURI **aManifestURI)
+{
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    NS_IF_ADDREF(*aManifestURI = mManifestURI);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::GetSucceeded(bool *aSucceeded)
+{
+    NS_ENSURE_TRUE(mState == STATE_FINISHED, NS_ERROR_NOT_AVAILABLE);
+
+    *aSucceeded = mSucceeded;
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::GetIsUpgrade(bool *aIsUpgrade)
+{
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    *aIsUpgrade = (mPreviousApplicationCache != nullptr);
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdate::AddURI(nsIURI *aURI, uint32_t aType, uint32_t aLoadFlags)
+{
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    if (mState >= STATE_DOWNLOADING)
+        return NS_ERROR_NOT_AVAILABLE;
+
+    // Resource URIs must have the same scheme as the manifest.
+    nsAutoCString scheme;
+    aURI->GetScheme(scheme);
+
+    bool match;
+    if (NS_FAILED(mManifestURI->SchemeIs(scheme.get(), &match)) || !match)
+        return NS_ERROR_FAILURE;
+
+    // Don't fetch the same URI twice.
+    for (uint32_t i = 0; i < mItems.Length(); i++) {
+        bool equals;
+        if (NS_SUCCEEDED(mItems[i]->mURI->Equals(aURI, &equals)) && equals &&
+            mItems[i]->mLoadFlags == aLoadFlags) {
+            // retain both types.
+            mItems[i]->mItemType |= aType;
+            return NS_OK;
+        }
+    }
+
+    RefPtr<nsOfflineCacheUpdateItem> item =
+        new nsOfflineCacheUpdateItem(aURI,
+                                     mDocumentURI,
+                                     mLoadingPrincipal,
+                                     mApplicationCache,
+                                     mPreviousApplicationCache,
+                                     aType,
+                                     aLoadFlags);
+    if (!item) return NS_ERROR_OUT_OF_MEMORY;
+
+    mItems.AppendElement(item);
+    mAddedItems = true;
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::AddDynamicURI(nsIURI *aURI)
+{
+    if (GeckoProcessType_Default != XRE_GetProcessType())
+        return NS_ERROR_NOT_IMPLEMENTED;
+
+    // If this is a partial update and the resource is already in the
+    // cache, we should only mark the entry, not fetch it again.
+    if (mPartialUpdate) {
+        nsAutoCString key;
+        GetCacheKey(aURI, key);
+
+        uint32_t types;
+        nsresult rv = mApplicationCache->GetTypes(key, &types);
+        if (NS_SUCCEEDED(rv)) {
+            if (!(types & nsIApplicationCache::ITEM_DYNAMIC)) {
+                mApplicationCache->MarkEntry
+                    (key, nsIApplicationCache::ITEM_DYNAMIC);
+            }
+            return NS_OK;
+        }
+    }
+
+    return AddURI(aURI, nsIApplicationCache::ITEM_DYNAMIC);
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::Cancel()
+{
+    LOG(("nsOfflineCacheUpdate::Cancel [%p]", this));
+
+    if ((mState == STATE_FINISHED) || (mState == STATE_CANCELLED)) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    mState = STATE_CANCELLED;
+    mSucceeded = false;
+
+    // Cancel all running downloads
+    for (uint32_t i = 0; i < mItems.Length(); ++i) {
+        nsOfflineCacheUpdateItem * item = mItems[i];
+
+        if (item->IsInProgress())
+            item->Cancel();
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::AddObserver(nsIOfflineCacheUpdateObserver *aObserver,
+                                  bool aHoldWeak)
+{
+    LOG(("nsOfflineCacheUpdate::AddObserver [%p] to update [%p]", aObserver, this));
+
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    if (aHoldWeak) {
+        nsCOMPtr<nsIWeakReference> weakRef = do_GetWeakReference(aObserver);
+        mWeakObservers.AppendObject(weakRef);
+    } else {
+        mObservers.AppendObject(aObserver);
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::RemoveObserver(nsIOfflineCacheUpdateObserver *aObserver)
+{
+    LOG(("nsOfflineCacheUpdate::RemoveObserver [%p] from update [%p]", aObserver, this));
+
+    NS_ENSURE_TRUE(mState >= STATE_INITIALIZED, NS_ERROR_NOT_INITIALIZED);
+
+    for (int32_t i = 0; i < mWeakObservers.Count(); i++) {
+        nsCOMPtr<nsIOfflineCacheUpdateObserver> observer =
+            do_QueryReferent(mWeakObservers[i]);
+        if (observer == aObserver) {
+            mWeakObservers.RemoveObjectAt(i);
+            return NS_OK;
+        }
+    }
+
+    for (int32_t i = 0; i < mObservers.Count(); i++) {
+        if (mObservers[i] == aObserver) {
+            mObservers.RemoveObjectAt(i);
+            return NS_OK;
+        }
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::GetByteProgress(uint64_t * _result)
+{
+    NS_ENSURE_ARG(_result);
+
+    *_result = mByteProgress;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::Schedule()
+{
+    LOG(("nsOfflineCacheUpdate::Schedule [%p]", this));
+
+    nsOfflineCacheUpdateService* service =
+        nsOfflineCacheUpdateService::EnsureService();
+
+    if (!service) {
+        return NS_ERROR_FAILURE;
+    }
+
+    return service->ScheduleUpdate(this);
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::UpdateStateChanged(nsIOfflineCacheUpdate *aUpdate,
+                                         uint32_t aState)
+{
+    if (aState == nsIOfflineCacheUpdateObserver::STATE_FINISHED) {
+        // Take the mSucceeded flag from the underlying update, we will be
+        // queried for it soon. mSucceeded of this update is false (manifest
+        // check failed) but the subsequent re-fetch update might succeed
+        bool succeeded;
+        aUpdate->GetSucceeded(&succeeded);
+        mSucceeded = succeeded;
+    }
+
+    NotifyState(aState);
+    if (aState == nsIOfflineCacheUpdateObserver::STATE_FINISHED)
+        aUpdate->RemoveObserver(this);
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::ApplicationCacheAvailable(nsIApplicationCache *applicationCache)
+{
+    AssociateDocuments(applicationCache);
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdate::nsIRunable
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsOfflineCacheUpdate::Run()
+{
+    ProcessNextURI();
+    return NS_OK;
+}
diff --git a/uriloader/prefetch/nsOfflineCacheUpdate.h b/uriloader/prefetch/nsOfflineCacheUpdate.h
new file mode 100644
index 0000000000..4ccba41359
--- /dev/null
+++ b/uriloader/prefetch/nsOfflineCacheUpdate.h
@@ -0,0 +1,381 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#ifndef nsOfflineCacheUpdate_h__
+#define nsOfflineCacheUpdate_h__
+
+#include "nsIOfflineCacheUpdate.h"
+
+#include "nsAutoPtr.h"
+#include "nsCOMArray.h"
+#include "nsCOMPtr.h"
+#include "nsIChannelEventSink.h"
+#include "nsIDOMDocument.h"
+#include "nsIDOMNode.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIMutableArray.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "nsIApplicationCache.h"
+#include "nsIRequestObserver.h"
+#include "nsIRunnable.h"
+#include "nsIStreamListener.h"
+#include "nsIURI.h"
+#include "nsIWebProgressListener.h"
+#include "nsClassHashtable.h"
+#include "nsString.h"
+#include "nsTArray.h"
+#include "nsWeakReference.h"
+#include "nsICryptoHash.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/WeakPtr.h"
+#include "nsTHashtable.h"
+#include "nsHashKeys.h"
+
+class nsOfflineCacheUpdate;
+
+class nsOfflineCacheUpdateItem : public nsIStreamListener
+                               , public nsIRunnable
+                               , public nsIInterfaceRequestor
+                               , public nsIChannelEventSink
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIREQUESTOBSERVER
+    NS_DECL_NSISTREAMLISTENER
+    NS_DECL_NSIRUNNABLE
+    NS_DECL_NSIINTERFACEREQUESTOR
+    NS_DECL_NSICHANNELEVENTSINK
+
+    nsOfflineCacheUpdateItem(nsIURI *aURI,
+                             nsIURI *aReferrerURI,
+                             nsIPrincipal* aLoadingPrincipal,
+                             nsIApplicationCache *aApplicationCache,
+                             nsIApplicationCache *aPreviousApplicationCache,
+                             uint32_t aType,
+                             uint32_t aLoadFlags);
+
+    nsCOMPtr<nsIURI>              mURI;
+    nsCOMPtr<nsIURI>              mReferrerURI;
+    nsCOMPtr<nsIPrincipal>        mLoadingPrincipal;
+    nsCOMPtr<nsIApplicationCache> mApplicationCache;
+    nsCOMPtr<nsIApplicationCache> mPreviousApplicationCache;
+    nsCString                     mCacheKey;
+    uint32_t                      mItemType;
+    uint32_t                      mLoadFlags;
+
+    nsresult OpenChannel(nsOfflineCacheUpdate *aUpdate);
+    nsresult Cancel();
+    nsresult GetRequestSucceeded(bool * succeeded);
+
+    bool IsInProgress();
+    bool IsScheduled();
+    bool IsCompleted();
+
+    nsresult GetStatus(uint16_t *aStatus);
+
+private:
+    enum LoadStatus : uint16_t {
+      UNINITIALIZED = 0U,
+      REQUESTED = 1U,
+      RECEIVING = 2U,
+      LOADED = 3U
+    };
+
+    RefPtr<nsOfflineCacheUpdate> mUpdate;
+    nsCOMPtr<nsIChannel>           mChannel;
+    uint16_t                       mState;
+
+protected:
+    virtual ~nsOfflineCacheUpdateItem();
+
+    int64_t                        mBytesRead;
+};
+
+
+class nsOfflineManifestItem : public nsOfflineCacheUpdateItem
+{
+public:
+    NS_DECL_NSISTREAMLISTENER
+    NS_DECL_NSIREQUESTOBSERVER
+
+    nsOfflineManifestItem(nsIURI *aURI,
+                          nsIURI *aReferrerURI,
+                          nsIPrincipal* aLoadingPrincipal,
+                          nsIApplicationCache *aApplicationCache,
+                          nsIApplicationCache *aPreviousApplicationCache);
+    virtual ~nsOfflineManifestItem();
+
+    nsCOMArray<nsIURI> &GetExplicitURIs() { return mExplicitURIs; }
+    nsCOMArray<nsIURI> &GetAnonymousURIs() { return mAnonymousURIs; }
+    nsCOMArray<nsIURI> &GetFallbackURIs() { return mFallbackURIs; }
+
+    nsTArray<nsCString> &GetOpportunisticNamespaces()
+        { return mOpportunisticNamespaces; }
+    nsIArray *GetNamespaces()
+        { return mNamespaces.get(); }
+
+    bool ParseSucceeded()
+        { return (mParserState != PARSE_INIT && mParserState != PARSE_ERROR); }
+    bool NeedsUpdate() { return mParserState != PARSE_INIT && mNeedsUpdate; }
+
+    void GetManifestHash(nsCString &aManifestHash)
+        { aManifestHash = mManifestHashValue; }
+
+private:
+    static nsresult ReadManifest(nsIInputStream *aInputStream,
+                                 void *aClosure,
+                                 const char *aFromSegment,
+                                 uint32_t aOffset,
+                                 uint32_t aCount,
+                                 uint32_t *aBytesConsumed);
+
+    nsresult AddNamespace(uint32_t namespaceType,
+                          const nsCString &namespaceSpec,
+                          const nsCString &data);
+
+    nsresult HandleManifestLine(const nsCString::const_iterator &aBegin,
+                                const nsCString::const_iterator &aEnd);
+
+    /**
+     * Saves "offline-manifest-hash" meta data from the old offline cache
+     * token to mOldManifestHashValue member to be compared on
+     * successfull load.
+     */
+    nsresult GetOldManifestContentHash(nsIRequest *aRequest);
+    /**
+     * This method setups the mNeedsUpdate to false when hash value
+     * of the just downloaded manifest file is the same as stored in cache's 
+     * "offline-manifest-hash" meta data. Otherwise stores the new value
+     * to this meta data.
+     */
+    nsresult CheckNewManifestContentHash(nsIRequest *aRequest);
+
+    void ReadStrictFileOriginPolicyPref();
+
+    enum {
+        PARSE_INIT,
+        PARSE_CACHE_ENTRIES,
+        PARSE_FALLBACK_ENTRIES,
+        PARSE_BYPASS_ENTRIES,
+        PARSE_UNKNOWN_SECTION,
+        PARSE_ERROR
+    } mParserState;
+
+    nsCString mReadBuf;
+
+    nsCOMArray<nsIURI> mExplicitURIs;
+    nsCOMArray<nsIURI> mAnonymousURIs;
+    nsCOMArray<nsIURI> mFallbackURIs;
+
+    // All opportunistic caching namespaces.  Used to decide whether
+    // to include previously-opportunistically-cached entries.
+    nsTArray<nsCString> mOpportunisticNamespaces;
+
+    // Array of nsIApplicationCacheNamespace objects specified by the
+    // manifest.
+    nsCOMPtr<nsIMutableArray> mNamespaces;
+
+    bool mNeedsUpdate;
+    bool mStrictFileOriginPolicy;
+
+    // manifest hash data
+    nsCOMPtr<nsICryptoHash> mManifestHash;
+    bool mManifestHashInitialized;
+    nsCString mManifestHashValue;
+    nsCString mOldManifestHashValue;
+};
+
+class nsOfflineCacheUpdateOwner
+  : public mozilla::SupportsWeakPtr<nsOfflineCacheUpdateOwner>
+{
+public:
+    MOZ_DECLARE_WEAKREFERENCE_TYPENAME(nsOfflineCacheUpdateOwner)
+    virtual ~nsOfflineCacheUpdateOwner() {}
+    virtual nsresult UpdateFinished(nsOfflineCacheUpdate *aUpdate) = 0;
+};
+
+class nsOfflineCacheUpdate final : public nsIOfflineCacheUpdate
+                                 , public nsIOfflineCacheUpdateObserver
+                                 , public nsIRunnable
+                                 , public nsOfflineCacheUpdateOwner
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIOFFLINECACHEUPDATE
+    NS_DECL_NSIOFFLINECACHEUPDATEOBSERVER
+    NS_DECL_NSIRUNNABLE
+
+    nsOfflineCacheUpdate();
+
+    static nsresult GetCacheKey(nsIURI *aURI, nsACString &aKey);
+
+    nsresult Init();
+
+    nsresult Begin();
+
+    void LoadCompleted(nsOfflineCacheUpdateItem *aItem);
+    void ManifestCheckCompleted(nsresult aStatus,
+                                const nsCString &aManifestHash);
+    void StickDocument(nsIURI *aDocumentURI);
+
+    void SetOwner(nsOfflineCacheUpdateOwner *aOwner);
+
+    bool IsForGroupID(const nsCSubstring &groupID);
+    bool IsForProfile(nsIFile* aCustomProfileDir);
+
+    virtual nsresult UpdateFinished(nsOfflineCacheUpdate *aUpdate) override;
+
+protected:
+    ~nsOfflineCacheUpdate();
+
+    friend class nsOfflineCacheUpdateItem;
+    void OnByteProgress(uint64_t byteIncrement);
+
+private:
+    nsresult InitInternal(nsIURI *aManifestURI, nsIPrincipal* aPrincipal);
+    nsresult HandleManifest(bool *aDoUpdate);
+    nsresult AddURI(nsIURI *aURI, uint32_t aItemType, uint32_t aLoadFlags = 0);
+
+    nsresult ProcessNextURI();
+
+    // Adds items from the previous cache witha type matching aType.
+    // If namespaceFilter is non-null, only items matching the
+    // specified namespaces will be added.
+    nsresult AddExistingItems(uint32_t aType,
+                              nsTArray<nsCString>* namespaceFilter = nullptr);
+    nsresult ScheduleImplicit();
+    void AssociateDocuments(nsIApplicationCache* cache);
+    bool CheckUpdateAvailability();
+    void NotifyUpdateAvailability(bool updateAvailable);
+
+    void GatherObservers(nsCOMArray<nsIOfflineCacheUpdateObserver> &aObservers);
+    void NotifyState(uint32_t state);
+    nsresult Finish();
+    nsresult FinishNoNotify();
+
+    void AsyncFinishWithError();
+
+    // Find one non-pinned cache group and evict it.
+    nsresult EvictOneNonPinned();
+
+    enum {
+        STATE_UNINITIALIZED,
+        STATE_INITIALIZED,
+        STATE_CHECKING,
+        STATE_DOWNLOADING,
+        STATE_CANCELLED,
+        STATE_FINISHED
+    } mState;
+
+    mozilla::WeakPtr<nsOfflineCacheUpdateOwner> mOwner;
+
+    bool mAddedItems;
+    bool mPartialUpdate;
+    bool mOnlyCheckUpdate;
+    bool mSucceeded;
+    bool mObsolete;
+
+    nsCString mUpdateDomain;
+    nsCString mGroupID;
+    nsCOMPtr<nsIURI> mManifestURI;
+    nsCOMPtr<nsIURI> mDocumentURI;
+    nsCOMPtr<nsIPrincipal> mLoadingPrincipal;
+    nsCOMPtr<nsIFile> mCustomProfileDir;
+
+    nsCOMPtr<nsIObserver> mUpdateAvailableObserver;
+
+    nsCOMPtr<nsIApplicationCache> mApplicationCache;
+    nsCOMPtr<nsIApplicationCache> mPreviousApplicationCache;
+
+    nsCOMPtr<nsIObserverService> mObserverService;
+
+    RefPtr<nsOfflineManifestItem> mManifestItem;
+
+    /* Items being updated */
+    uint32_t mItemsInProgress;
+    nsTArray<RefPtr<nsOfflineCacheUpdateItem> > mItems;
+
+    /* Clients watching this update for changes */
+    nsCOMArray<nsIWeakReference> mWeakObservers;
+    nsCOMArray<nsIOfflineCacheUpdateObserver> mObservers;
+
+    /* Documents that requested this update */
+    nsCOMArray<nsIURI> mDocumentURIs;
+
+    /* Reschedule count.  When an update is rescheduled due to
+     * mismatched manifests, the reschedule count will be increased. */
+    uint32_t mRescheduleCount;
+
+    /* Whena an entry for a pinned app is retried, retries count is
+     * increaded. */
+    uint32_t mPinnedEntryRetriesCount;
+
+    RefPtr<nsOfflineCacheUpdate> mImplicitUpdate;
+
+    bool                           mPinned;
+
+    uint64_t                       mByteProgress;
+};
+
+class nsOfflineCacheUpdateService final : public nsIOfflineCacheUpdateService
+                                        , public nsIObserver
+                                        , public nsOfflineCacheUpdateOwner
+                                        , public nsSupportsWeakReference
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIOFFLINECACHEUPDATESERVICE
+    NS_DECL_NSIOBSERVER
+
+    nsOfflineCacheUpdateService();
+
+    nsresult Init();
+
+    nsresult ScheduleUpdate(nsOfflineCacheUpdate *aUpdate);
+    nsresult FindUpdate(nsIURI *aManifestURI,
+                        nsACString const &aOriginSuffix,
+                        nsIFile *aCustomProfileDir,
+                        nsOfflineCacheUpdate **aUpdate);
+
+    nsresult Schedule(nsIURI *aManifestURI,
+                      nsIURI *aDocumentURI,
+                      nsIPrincipal* aLoadingPrincipal,
+                      nsIDOMDocument *aDocument,
+                      nsPIDOMWindowInner* aWindow,
+                      nsIFile* aCustomProfileDir,
+                      nsIOfflineCacheUpdate **aUpdate);
+
+    virtual nsresult UpdateFinished(nsOfflineCacheUpdate *aUpdate) override;
+
+    /**
+     * Returns the singleton nsOfflineCacheUpdateService without an addref, or
+     * nullptr if the service couldn't be created.
+     */
+    static nsOfflineCacheUpdateService *EnsureService();
+
+    /** Addrefs and returns the singleton nsOfflineCacheUpdateService. */
+    static nsOfflineCacheUpdateService *GetInstance();
+
+    static nsresult OfflineAppPinnedForURI(nsIURI *aDocumentURI,
+                                           nsIPrefBranch *aPrefBranch,
+                                           bool *aPinned);
+
+    static nsTHashtable<nsCStringHashKey>* AllowedDomains();
+
+private:
+    ~nsOfflineCacheUpdateService();
+
+    nsresult ProcessNextUpdate();
+
+    nsTArray<RefPtr<nsOfflineCacheUpdate> > mUpdates;
+    static nsTHashtable<nsCStringHashKey>* mAllowedDomains;
+
+    bool mDisabled;
+    bool mUpdateRunning;
+    bool mLowFreeSpace;
+};
+
+#endif
diff --git a/uriloader/prefetch/nsOfflineCacheUpdateService.cpp b/uriloader/prefetch/nsOfflineCacheUpdateService.cpp
new file mode 100644
index 0000000000..adb3fd5160
--- /dev/null
+++ b/uriloader/prefetch/nsOfflineCacheUpdateService.cpp
@@ -0,0 +1,736 @@
+/* -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "OfflineCacheUpdateChild.h"
+#include "OfflineCacheUpdateParent.h"
+#include "nsXULAppAPI.h"
+#include "OfflineCacheUpdateGlue.h"
+#include "nsOfflineCacheUpdate.h"
+
+#include "nsCPrefetchService.h"
+#include "nsCURILoader.h"
+#include "nsIApplicationCacheContainer.h"
+#include "nsIApplicationCacheChannel.h"
+#include "nsIApplicationCacheService.h"
+#include "nsICachingChannel.h"
+#include "nsIContent.h"
+#include "nsIDocShell.h"
+#include "nsIDocumentLoader.h"
+#include "nsIDOMElement.h"
+#include "nsIDOMWindow.h"
+#include "nsIDOMOfflineResourceList.h"
+#include "nsIDocument.h"
+#include "nsIObserverService.h"
+#include "nsIURL.h"
+#include "nsIWebProgress.h"
+#include "nsIWebNavigation.h"
+#include "nsICryptoHash.h"
+#include "nsIPermissionManager.h"
+#include "nsIPrincipal.h"
+#include "nsNetCID.h"
+#include "nsServiceManagerUtils.h"
+#include "nsStreamUtils.h"
+#include "nsThreadUtils.h"
+#include "nsProxyRelease.h"
+#include "mozilla/Logging.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Unused.h"
+#include "nsIDiskSpaceWatcher.h"
+#include "nsIDocShell.h"
+#include "nsIDocShellTreeItem.h"
+#include "nsIDocShellTreeOwner.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/PermissionMessageUtils.h"
+#include "nsContentUtils.h"
+#include "mozilla/Unused.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+static nsOfflineCacheUpdateService *gOfflineCacheUpdateService = nullptr;
+static bool sAllowOfflineCache = true;
+
+nsTHashtable<nsCStringHashKey>* nsOfflineCacheUpdateService::mAllowedDomains = nullptr;
+
+nsTHashtable<nsCStringHashKey>* nsOfflineCacheUpdateService::AllowedDomains()
+{
+    if (!mAllowedDomains)
+        mAllowedDomains = new nsTHashtable<nsCStringHashKey>();
+
+    return mAllowedDomains;
+}
+
+
+typedef mozilla::docshell::OfflineCacheUpdateParent OfflineCacheUpdateParent;
+typedef mozilla::docshell::OfflineCacheUpdateChild OfflineCacheUpdateChild;
+typedef mozilla::docshell::OfflineCacheUpdateGlue OfflineCacheUpdateGlue;
+
+//
+// To enable logging (see mozilla/Logging.h for full details):
+//
+//    set MOZ_LOG=nsOfflineCacheUpdate:5
+//    set MOZ_LOG_FILE=offlineupdate.log
+//
+// this enables LogLevel::Debug level information and places all output in
+// the file offlineupdate.log
+//
+LazyLogModule gOfflineCacheUpdateLog("nsOfflineCacheUpdate");
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug, args)
+
+#undef LOG_ENABLED
+#define LOG_ENABLED() MOZ_LOG_TEST(gOfflineCacheUpdateLog, mozilla::LogLevel::Debug)
+
+//-----------------------------------------------------------------------------
+// nsOfflineCachePendingUpdate
+//-----------------------------------------------------------------------------
+
+class nsOfflineCachePendingUpdate final : public nsIWebProgressListener
+                                        , public nsSupportsWeakReference
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIWEBPROGRESSLISTENER
+
+    nsOfflineCachePendingUpdate(nsOfflineCacheUpdateService *aService,
+                                nsIURI *aManifestURI,
+                                nsIURI *aDocumentURI,
+                                nsIPrincipal* aLoadingPrincipal,
+                                nsIDOMDocument *aDocument)
+        : mService(aService)
+        , mManifestURI(aManifestURI)
+        , mDocumentURI(aDocumentURI)
+        , mLoadingPrincipal(aLoadingPrincipal)
+        , mDidReleaseThis(false)
+        {
+            mDocument = do_GetWeakReference(aDocument);
+        }
+
+private:
+    ~nsOfflineCachePendingUpdate() {}
+
+    RefPtr<nsOfflineCacheUpdateService> mService;
+    nsCOMPtr<nsIURI> mManifestURI;
+    nsCOMPtr<nsIURI> mDocumentURI;
+    nsCOMPtr<nsIPrincipal> mLoadingPrincipal;
+    nsCOMPtr<nsIWeakReference> mDocument;
+    bool mDidReleaseThis;
+};
+
+NS_IMPL_ISUPPORTS(nsOfflineCachePendingUpdate,
+                  nsIWebProgressListener,
+                  nsISupportsWeakReference)
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateService::nsIWebProgressListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsOfflineCachePendingUpdate::OnProgressChange(nsIWebProgress *aProgress,
+                                              nsIRequest *aRequest,
+                                              int32_t curSelfProgress,
+                                              int32_t maxSelfProgress,
+                                              int32_t curTotalProgress,
+                                              int32_t maxTotalProgress)
+{
+    NS_NOTREACHED("notification excluded in AddProgressListener(...)");
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCachePendingUpdate::OnStateChange(nsIWebProgress* aWebProgress,
+                                           nsIRequest *aRequest,
+                                           uint32_t progressStateFlags,
+                                           nsresult aStatus)
+{
+    if (mDidReleaseThis) {
+        return NS_OK;
+    }
+    nsCOMPtr<nsIDOMDocument> updateDoc = do_QueryReferent(mDocument);
+    if (!updateDoc) {
+        // The document that scheduled this update has gone away,
+        // we don't need to listen anymore.
+        aWebProgress->RemoveProgressListener(this);
+        MOZ_ASSERT(!mDidReleaseThis);
+        mDidReleaseThis = true;
+        NS_RELEASE_THIS();
+        return NS_OK;
+    }
+
+    if (!(progressStateFlags & STATE_STOP)) {
+        return NS_OK;
+    }
+
+    nsCOMPtr<mozIDOMWindowProxy> windowProxy;
+    aWebProgress->GetDOMWindow(getter_AddRefs(windowProxy));
+    if (!windowProxy) return NS_OK;
+
+    auto* outerWindow = nsPIDOMWindowOuter::From(windowProxy);
+    nsPIDOMWindowInner* innerWindow = outerWindow->GetCurrentInnerWindow();
+
+    nsCOMPtr<nsIDocument> progressDoc = outerWindow->GetDoc();
+    if (!progressDoc) return NS_OK;
+
+    if (!SameCOMIdentity(progressDoc, updateDoc)) {
+        return NS_OK;
+    }
+
+    LOG(("nsOfflineCachePendingUpdate::OnStateChange [%p, doc=%p]",
+         this, progressDoc.get()));
+
+    // Only schedule the update if the document loaded successfully
+    if (NS_SUCCEEDED(aStatus)) {
+        nsCOMPtr<nsIOfflineCacheUpdate> update;
+        mService->Schedule(mManifestURI, mDocumentURI, mLoadingPrincipal, updateDoc, innerWindow,
+                           nullptr, getter_AddRefs(update));
+        if (mDidReleaseThis) {
+            return NS_OK;
+        }
+    }
+
+    aWebProgress->RemoveProgressListener(this);
+    MOZ_ASSERT(!mDidReleaseThis);
+    mDidReleaseThis = true;
+    NS_RELEASE_THIS();
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCachePendingUpdate::OnLocationChange(nsIWebProgress* aWebProgress,
+                                              nsIRequest* aRequest,
+                                              nsIURI *location,
+                                              uint32_t aFlags)
+{
+    NS_NOTREACHED("notification excluded in AddProgressListener(...)");
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCachePendingUpdate::OnStatusChange(nsIWebProgress* aWebProgress,
+                                            nsIRequest* aRequest,
+                                            nsresult aStatus,
+                                            const char16_t* aMessage)
+{
+    NS_NOTREACHED("notification excluded in AddProgressListener(...)");
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCachePendingUpdate::OnSecurityChange(nsIWebProgress *aWebProgress,
+                                              nsIRequest *aRequest,
+                                              uint32_t state)
+{
+    NS_NOTREACHED("notification excluded in AddProgressListener(...)");
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateService::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsOfflineCacheUpdateService,
+                  nsIOfflineCacheUpdateService,
+                  nsIObserver,
+                  nsISupportsWeakReference)
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateService <public>
+//-----------------------------------------------------------------------------
+
+nsOfflineCacheUpdateService::nsOfflineCacheUpdateService()
+    : mDisabled(false)
+    , mUpdateRunning(false)
+    , mLowFreeSpace(false)
+{
+    MOZ_ASSERT(NS_IsMainThread());
+    Preferences::AddBoolVarCache(&sAllowOfflineCache,
+                                 "browser.cache.offline.enable",
+                                 true);
+}
+
+nsOfflineCacheUpdateService::~nsOfflineCacheUpdateService()
+{
+    gOfflineCacheUpdateService = nullptr;
+}
+
+nsresult
+nsOfflineCacheUpdateService::Init()
+{
+    // Observe xpcom-shutdown event
+    nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+    if (!observerService)
+      return NS_ERROR_FAILURE;
+
+    nsresult rv = observerService->AddObserver(this,
+                                               NS_XPCOM_SHUTDOWN_OBSERVER_ID,
+                                               true);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Get the current status of the disk in terms of free space and observe
+    // low device storage notifications.
+    nsCOMPtr<nsIDiskSpaceWatcher> diskSpaceWatcherService =
+      do_GetService("@mozilla.org/toolkit/disk-space-watcher;1");
+    if (diskSpaceWatcherService) {
+      diskSpaceWatcherService->GetIsDiskFull(&mLowFreeSpace);
+    } else {
+      NS_WARNING("Could not get disk status from nsIDiskSpaceWatcher");
+    }
+
+    rv = observerService->AddObserver(this, "disk-space-watcher", false);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    gOfflineCacheUpdateService = this;
+
+    return NS_OK;
+}
+
+/* static */
+nsOfflineCacheUpdateService *
+nsOfflineCacheUpdateService::GetInstance()
+{
+    if (!gOfflineCacheUpdateService) {
+        gOfflineCacheUpdateService = new nsOfflineCacheUpdateService();
+        if (!gOfflineCacheUpdateService)
+            return nullptr;
+        NS_ADDREF(gOfflineCacheUpdateService);
+        nsresult rv = gOfflineCacheUpdateService->Init();
+        if (NS_FAILED(rv)) {
+            NS_RELEASE(gOfflineCacheUpdateService);
+            return nullptr;
+        }
+        return gOfflineCacheUpdateService;
+    }
+
+    NS_ADDREF(gOfflineCacheUpdateService);
+
+    return gOfflineCacheUpdateService;
+}
+
+/* static */
+nsOfflineCacheUpdateService *
+nsOfflineCacheUpdateService::EnsureService()
+{
+    if (!gOfflineCacheUpdateService) {
+        // Make the service manager hold a long-lived reference to the service
+        nsCOMPtr<nsIOfflineCacheUpdateService> service =
+            do_GetService(NS_OFFLINECACHEUPDATESERVICE_CONTRACTID);
+    }
+
+    return gOfflineCacheUpdateService;
+}
+
+nsresult
+nsOfflineCacheUpdateService::ScheduleUpdate(nsOfflineCacheUpdate *aUpdate)
+{
+    LOG(("nsOfflineCacheUpdateService::Schedule [%p, update=%p]",
+         this, aUpdate));
+
+    aUpdate->SetOwner(this);
+
+    mUpdates.AppendElement(aUpdate);
+    ProcessNextUpdate();
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::ScheduleOnDocumentStop(nsIURI *aManifestURI,
+                                                    nsIURI *aDocumentURI,
+                                                    nsIPrincipal* aLoadingPrincipal,
+                                                    nsIDOMDocument *aDocument)
+{
+    LOG(("nsOfflineCacheUpdateService::ScheduleOnDocumentStop [%p, manifestURI=%p, documentURI=%p doc=%p]",
+         this, aManifestURI, aDocumentURI, aDocument));
+
+    nsCOMPtr<nsIDocument> doc = do_QueryInterface(aDocument);
+    nsCOMPtr<nsIWebProgress> progress = do_QueryInterface(doc->GetContainer());
+    NS_ENSURE_TRUE(progress, NS_ERROR_INVALID_ARG);
+
+    // Proceed with cache update
+    RefPtr<nsOfflineCachePendingUpdate> update =
+        new nsOfflineCachePendingUpdate(this, aManifestURI, aDocumentURI,
+                                        aLoadingPrincipal, aDocument);
+    NS_ENSURE_TRUE(update, NS_ERROR_OUT_OF_MEMORY);
+
+    nsresult rv = progress->AddProgressListener
+        (update, nsIWebProgress::NOTIFY_STATE_DOCUMENT);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // The update will release when it has scheduled itself.
+    Unused << update.forget();
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdateService::UpdateFinished(nsOfflineCacheUpdate *aUpdate)
+{
+    LOG(("nsOfflineCacheUpdateService::UpdateFinished [%p, update=%p]",
+         this, aUpdate));
+
+    NS_ASSERTION(mUpdates.Length() > 0 &&
+                 mUpdates[0] == aUpdate, "Unknown update completed");
+
+    // keep this item alive until we're done notifying observers
+    RefPtr<nsOfflineCacheUpdate> update = mUpdates[0];
+    Unused << update;
+    mUpdates.RemoveElementAt(0);
+    mUpdateRunning = false;
+
+    ProcessNextUpdate();
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateService <private>
+//-----------------------------------------------------------------------------
+
+nsresult
+nsOfflineCacheUpdateService::ProcessNextUpdate()
+{
+    LOG(("nsOfflineCacheUpdateService::ProcessNextUpdate [%p, num=%d]",
+         this, mUpdates.Length()));
+
+    if (mDisabled)
+        return NS_ERROR_ABORT;
+
+    if (mUpdateRunning)
+        return NS_OK;
+
+    if (mUpdates.Length() > 0) {
+        mUpdateRunning = true;
+        // Canceling the update before Begin() call will make the update
+        // asynchronously finish with an error.
+        if (mLowFreeSpace) {
+            mUpdates[0]->Cancel();
+        }
+        return mUpdates[0]->Begin();
+    }
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateService::nsIOfflineCacheUpdateService
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::GetNumUpdates(uint32_t *aNumUpdates)
+{
+    LOG(("nsOfflineCacheUpdateService::GetNumUpdates [%p]", this));
+
+    *aNumUpdates = mUpdates.Length();
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::GetUpdate(uint32_t aIndex,
+                                       nsIOfflineCacheUpdate **aUpdate)
+{
+    LOG(("nsOfflineCacheUpdateService::GetUpdate [%p, %d]", this, aIndex));
+
+    if (aIndex < mUpdates.Length()) {
+        NS_ADDREF(*aUpdate = mUpdates[aIndex]);
+    } else {
+        *aUpdate = nullptr;
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsOfflineCacheUpdateService::FindUpdate(nsIURI *aManifestURI,
+                                        nsACString const &aOriginSuffix,
+                                        nsIFile *aCustomProfileDir,
+                                        nsOfflineCacheUpdate **aUpdate)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIApplicationCacheService> cacheService =
+        do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString groupID;
+    rv = cacheService->BuildGroupIDForSuffix(aManifestURI, aOriginSuffix, groupID);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    RefPtr<nsOfflineCacheUpdate> update;
+    for (uint32_t i = 0; i < mUpdates.Length(); i++) {
+        update = mUpdates[i];
+
+        bool partial;
+        rv = update->GetPartial(&partial);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        if (partial) {
+            // Partial updates aren't considered
+            continue;
+        }
+
+        if (update->IsForGroupID(groupID) && update->IsForProfile(aCustomProfileDir)) {
+            update.swap(*aUpdate);
+            return NS_OK;
+        }
+    }
+
+    return NS_ERROR_NOT_AVAILABLE;
+}
+
+nsresult
+nsOfflineCacheUpdateService::Schedule(nsIURI *aManifestURI,
+                                      nsIURI *aDocumentURI,
+                                      nsIPrincipal* aLoadingPrincipal,
+                                      nsIDOMDocument *aDocument,
+                                      nsPIDOMWindowInner* aWindow,
+                                      nsIFile* aCustomProfileDir,
+                                      nsIOfflineCacheUpdate **aUpdate)
+{
+    nsCOMPtr<nsIOfflineCacheUpdate> update;
+    if (GeckoProcessType_Default != XRE_GetProcessType()) {
+        update = new OfflineCacheUpdateChild(aWindow);
+    }
+    else {
+        update = new OfflineCacheUpdateGlue();
+    }
+
+    nsresult rv;
+
+    if (aWindow) {
+      // Ensure there is window.applicationCache object that is
+      // responsible for association of the new applicationCache
+      // with the corresponding document.  Just ignore the result.
+      nsCOMPtr<nsIDOMOfflineResourceList> appCacheWindowObject =
+          aWindow->GetApplicationCache();
+    }
+
+    rv = update->Init(aManifestURI, aDocumentURI, aLoadingPrincipal, aDocument,
+                      aCustomProfileDir);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = update->Schedule();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    NS_ADDREF(*aUpdate = update);
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::ScheduleUpdate(nsIURI *aManifestURI,
+                                            nsIURI *aDocumentURI,
+                                            nsIPrincipal* aLoadingPrincipal,
+                                            mozIDOMWindow* aWindow,
+                                            nsIOfflineCacheUpdate **aUpdate)
+{
+    return Schedule(aManifestURI, aDocumentURI, aLoadingPrincipal, nullptr,
+                    nsPIDOMWindowInner::From(aWindow), nullptr, aUpdate);
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::ScheduleAppUpdate(nsIURI *aManifestURI,
+                                               nsIURI *aDocumentURI,
+                                               nsIPrincipal* aLoadingPrincipal,
+                                               nsIFile *aProfileDir,
+                                               nsIOfflineCacheUpdate **aUpdate)
+{
+    return Schedule(aManifestURI, aDocumentURI, aLoadingPrincipal, nullptr, nullptr,
+                    aProfileDir, aUpdate);
+}
+
+NS_IMETHODIMP nsOfflineCacheUpdateService::CheckForUpdate(nsIURI *aManifestURI,
+                                                          nsIPrincipal* aLoadingPrincipal,
+                                                          nsIObserver *aObserver)
+{
+    if (GeckoProcessType_Default != XRE_GetProcessType()) {
+        // Not intended to support this on child processes
+        return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    nsCOMPtr<nsIOfflineCacheUpdate> update = new OfflineCacheUpdateGlue();
+
+    nsresult rv;
+
+    rv = update->InitForUpdateCheck(aManifestURI, aLoadingPrincipal, aObserver);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = update->Schedule();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateService::nsIObserver
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::Observe(nsISupports     *aSubject,
+                                     const char      *aTopic,
+                                     const char16_t *aData)
+{
+    if (!strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+        if (mUpdates.Length() > 0)
+            mUpdates[0]->Cancel();
+        mDisabled = true;
+    }
+
+    if (!strcmp(aTopic, "disk-space-watcher")) {
+        if (NS_LITERAL_STRING("full").Equals(aData)) {
+            mLowFreeSpace = true;
+            for (uint32_t i = 0; i < mUpdates.Length(); i++) {
+                mUpdates[i]->Cancel();
+            }
+        } else if (NS_LITERAL_STRING("free").Equals(aData)) {
+            mLowFreeSpace = false;
+        }
+    }
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsOfflineCacheUpdateService::nsIOfflineCacheUpdateService
+//-----------------------------------------------------------------------------
+
+static nsresult
+OfflineAppPermForPrincipal(nsIPrincipal *aPrincipal,
+                           nsIPrefBranch *aPrefBranch,
+                           bool pinned,
+                           bool *aAllowed)
+{
+    *aAllowed = false;
+
+    if (!sAllowOfflineCache) {
+        return NS_OK;
+    }
+
+    if (!aPrincipal)
+        return NS_ERROR_INVALID_ARG;
+
+    nsCOMPtr<nsIURI> uri;
+    aPrincipal->GetURI(getter_AddRefs(uri));
+
+    if (!uri)
+        return NS_OK;
+
+    nsCOMPtr<nsIURI> innerURI = NS_GetInnermostURI(uri);
+    if (!innerURI)
+        return NS_OK;
+
+    // only http and https applications can use offline APIs.
+    bool match;
+    nsresult rv = innerURI->SchemeIs("http", &match);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!match) {
+        rv = innerURI->SchemeIs("https", &match);
+        NS_ENSURE_SUCCESS(rv, rv);
+        if (!match) {
+            return NS_OK;
+        }
+    }
+
+    nsAutoCString domain;
+    rv = innerURI->GetAsciiHost(domain);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (nsOfflineCacheUpdateService::AllowedDomains()->Contains(domain)) {
+        *aAllowed = true;
+        return NS_OK;
+    }
+
+    nsCOMPtr<nsIPermissionManager> permissionManager =
+        services::GetPermissionManager();
+    if (!permissionManager) {
+        return NS_OK;
+    }
+
+    uint32_t perm;
+    const char *permName = pinned ? "pin-app" : "offline-app";
+    permissionManager->TestExactPermissionFromPrincipal(aPrincipal, permName, &perm);
+
+    if (perm == nsIPermissionManager::ALLOW_ACTION ||
+        perm == nsIOfflineCacheUpdateService::ALLOW_NO_WARN) {
+        *aAllowed = true;
+    }
+
+    // offline-apps.allow_by_default is now effective at the cache selection
+    // algorithm code (nsContentSink).
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::OfflineAppAllowed(nsIPrincipal *aPrincipal,
+                                               nsIPrefBranch *aPrefBranch,
+                                               bool *aAllowed)
+{
+    return OfflineAppPermForPrincipal(aPrincipal, aPrefBranch, false, aAllowed);
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::OfflineAppAllowedForURI(nsIURI *aURI,
+                                                     nsIPrefBranch *aPrefBranch,
+                                                     bool *aAllowed)
+{
+    PrincipalOriginAttributes attrs;
+    nsCOMPtr<nsIPrincipal> principal =
+        BasePrincipal::CreateCodebasePrincipal(aURI, attrs);
+    return OfflineAppPermForPrincipal(principal, aPrefBranch, false, aAllowed);
+}
+
+nsresult
+nsOfflineCacheUpdateService::OfflineAppPinnedForURI(nsIURI *aDocumentURI,
+                                                    nsIPrefBranch *aPrefBranch,
+                                                    bool *aPinned)
+{
+    PrincipalOriginAttributes attrs;
+    nsCOMPtr<nsIPrincipal> principal =
+        BasePrincipal::CreateCodebasePrincipal(aDocumentURI, attrs);
+    return OfflineAppPermForPrincipal(principal, aPrefBranch, true, aPinned);
+}
+
+NS_IMETHODIMP
+nsOfflineCacheUpdateService::AllowOfflineApp(nsIPrincipal *aPrincipal)
+{
+    nsresult rv;
+
+    if (!sAllowOfflineCache) {
+        return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    if (GeckoProcessType_Default != XRE_GetProcessType()) {
+        ContentChild* child = ContentChild::GetSingleton();
+
+        if (!child->SendSetOfflinePermission(IPC::Principal(aPrincipal))) {
+            return NS_ERROR_FAILURE;
+        }
+
+        nsAutoCString domain;
+        rv = aPrincipal->GetBaseDomain(domain);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        nsOfflineCacheUpdateService::AllowedDomains()->PutEntry(domain);
+    }
+    else {
+        nsCOMPtr<nsIPermissionManager> permissionManager =
+            services::GetPermissionManager();
+        if (!permissionManager)
+            return NS_ERROR_NOT_AVAILABLE;
+
+        rv = permissionManager->AddFromPrincipal(
+            aPrincipal, "offline-app", nsIPermissionManager::ALLOW_ACTION,
+            nsIPermissionManager::EXPIRE_NEVER, 0);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    return NS_OK;
+}
diff --git a/uriloader/prefetch/nsPrefetchService.cpp b/uriloader/prefetch/nsPrefetchService.cpp
new file mode 100644
index 0000000000..bd2b10d304
--- /dev/null
+++ b/uriloader/prefetch/nsPrefetchService.cpp
@@ -0,0 +1,931 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "nsPrefetchService.h"
+#include "nsICacheEntry.h"
+#include "nsIServiceManager.h"
+#include "nsICategoryManager.h"
+#include "nsIObserverService.h"
+#include "nsIWebProgress.h"
+#include "nsCURILoader.h"
+#include "nsICacheInfoChannel.h"
+#include "nsIHttpChannel.h"
+#include "nsIURL.h"
+#include "nsISimpleEnumerator.h"
+#include "nsNetUtil.h"
+#include "nsString.h"
+#include "nsXPIDLString.h"
+#include "nsReadableUtils.h"
+#include "nsStreamUtils.h"
+#include "nsAutoPtr.h"
+#include "prtime.h"
+#include "mozilla/Logging.h"
+#include "plstr.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/CORSMode.h"
+#include "mozilla/dom/HTMLLinkElement.h"
+#include "nsIDOMNode.h"
+#include "nsINode.h"
+#include "nsIDocument.h"
+#include "nsContentUtils.h"
+
+using namespace mozilla;
+
+//
+// To enable logging (see mozilla/Logging.h for full details):
+//
+//    set MOZ_LOG=nsPrefetch:5
+//    set MOZ_LOG_FILE=prefetch.log
+//
+// this enables LogLevel::Debug level information and places all output in
+// the file prefetch.log
+//
+static LazyLogModule gPrefetchLog("nsPrefetch");
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gPrefetchLog, mozilla::LogLevel::Debug, args)
+
+#undef LOG_ENABLED
+#define LOG_ENABLED() MOZ_LOG_TEST(gPrefetchLog, mozilla::LogLevel::Debug)
+
+#define PREFETCH_PREF "network.prefetch-next"
+#define PARALLELISM_PREF "network.prefetch-next.parallelism"
+#define AGGRESSIVE_PREF "network.prefetch-next.aggressive"
+
+//-----------------------------------------------------------------------------
+// helpers
+//-----------------------------------------------------------------------------
+
+static inline uint32_t
+PRTimeToSeconds(PRTime t_usec)
+{
+    PRTime usec_per_sec = PR_USEC_PER_SEC;
+    return uint32_t(t_usec /= usec_per_sec);
+}
+
+#define NowInSeconds() PRTimeToSeconds(PR_Now())
+
+//-----------------------------------------------------------------------------
+// nsPrefetchNode <public>
+//-----------------------------------------------------------------------------
+
+nsPrefetchNode::nsPrefetchNode(nsPrefetchService *aService,
+                               nsIURI *aURI,
+                               nsIURI *aReferrerURI,
+                               nsIDOMNode *aSource)
+    : mURI(aURI)
+    , mReferrerURI(aReferrerURI)
+    , mService(aService)
+    , mChannel(nullptr)
+    , mBytesRead(0)
+    , mShouldFireLoadEvent(false)
+{
+    nsCOMPtr<nsIWeakReference> source = do_GetWeakReference(aSource);
+    mSources.AppendElement(source);
+}
+
+nsresult
+nsPrefetchNode::OpenChannel()
+{
+    if (mSources.IsEmpty()) {
+        // Don't attempt to prefetch if we don't have a source node
+        // (which should never happen).
+        return NS_ERROR_FAILURE;
+    }
+    nsCOMPtr<nsINode> source;
+    while (!mSources.IsEmpty() && !(source = do_QueryReferent(mSources.ElementAt(0)))) {
+        // If source is null remove it.
+        // (which should never happen).
+        mSources.RemoveElementAt(0);
+    }
+
+    if (!source) {
+        // Don't attempt to prefetch if we don't have a source node
+        // (which should never happen).
+
+        return NS_ERROR_FAILURE;
+    }
+    nsCOMPtr<nsILoadGroup> loadGroup = source->OwnerDoc()->GetDocumentLoadGroup();
+    CORSMode corsMode = CORS_NONE;
+    net::ReferrerPolicy referrerPolicy = net::RP_Unset;
+    if (source->IsHTMLElement(nsGkAtoms::link)) {
+      dom::HTMLLinkElement* link = static_cast<dom::HTMLLinkElement*>(source.get());
+      corsMode = link->GetCORSMode();
+      referrerPolicy = link->GetLinkReferrerPolicy();
+    }
+
+    if (referrerPolicy == net::RP_Unset) {
+      referrerPolicy = source->OwnerDoc()->GetReferrerPolicy();
+    }
+
+    uint32_t securityFlags;
+    if (corsMode == CORS_NONE) {
+      securityFlags = nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_INHERITS;
+    } else {
+      securityFlags = nsILoadInfo::SEC_REQUIRE_CORS_DATA_INHERITS;
+      if (corsMode == CORS_USE_CREDENTIALS) {
+        securityFlags |= nsILoadInfo::SEC_COOKIES_INCLUDE;
+      }
+    }
+    nsresult rv = NS_NewChannelInternal(getter_AddRefs(mChannel),
+                                        mURI,
+                                        source,
+                                        source->NodePrincipal(),
+                                        nullptr,   //aTriggeringPrincipal
+                                        securityFlags,
+                                        nsIContentPolicy::TYPE_OTHER,
+                                        loadGroup, // aLoadGroup
+                                        this,      // aCallbacks
+                                        nsIRequest::LOAD_BACKGROUND |
+                                        nsICachingChannel::LOAD_ONLY_IF_MODIFIED);
+
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // configure HTTP specific stuff
+    nsCOMPtr<nsIHttpChannel> httpChannel =
+        do_QueryInterface(mChannel);
+    if (httpChannel) {
+        httpChannel->SetReferrerWithPolicy(mReferrerURI, referrerPolicy);
+        httpChannel->SetRequestHeader(
+            NS_LITERAL_CSTRING("X-Moz"),
+            NS_LITERAL_CSTRING("prefetch"),
+            false);
+    }
+
+    rv = mChannel->AsyncOpen2(this);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      // Drop the ref to the channel, because we don't want to end up with
+      // cycles through it.
+      mChannel = nullptr;
+    }
+    return rv;
+}
+
+nsresult
+nsPrefetchNode::CancelChannel(nsresult error)
+{
+    mChannel->Cancel(error);
+    mChannel = nullptr;
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchNode::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsPrefetchNode,
+                  nsIRequestObserver,
+                  nsIStreamListener,
+                  nsIInterfaceRequestor,
+                  nsIChannelEventSink,
+                  nsIRedirectResultListener)
+
+//-----------------------------------------------------------------------------
+// nsPrefetchNode::nsIStreamListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsPrefetchNode::OnStartRequest(nsIRequest *aRequest,
+                               nsISupports *aContext)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIHttpChannel> httpChannel =
+        do_QueryInterface(aRequest, &rv);
+    if (NS_FAILED(rv)) return rv;
+
+    // if the load is cross origin without CORS, or the CORS access is rejected,
+    // always fire load event to avoid leaking site information.
+    nsCOMPtr<nsILoadInfo> loadInfo = httpChannel->GetLoadInfo();
+    mShouldFireLoadEvent = loadInfo->GetTainting() == LoadTainting::Opaque ||
+                           (loadInfo->GetTainting() == LoadTainting::CORS &&
+                            (NS_FAILED(httpChannel->GetStatus(&rv)) ||
+                             NS_FAILED(rv)));
+
+    // no need to prefetch http error page
+    bool requestSucceeded;
+    if (NS_FAILED(httpChannel->GetRequestSucceeded(&requestSucceeded)) ||
+        !requestSucceeded) {
+      return NS_BINDING_ABORTED;
+    }
+
+    nsCOMPtr<nsICacheInfoChannel> cacheInfoChannel =
+        do_QueryInterface(aRequest, &rv);
+    if (NS_FAILED(rv)) return rv;
+ 
+    // no need to prefetch a document that is already in the cache
+    bool fromCache;
+    if (NS_SUCCEEDED(cacheInfoChannel->IsFromCache(&fromCache)) &&
+        fromCache) {
+        LOG(("document is already in the cache; canceling prefetch\n"));
+        // although it's canceled we still want to fire load event
+        mShouldFireLoadEvent = true;
+        return NS_BINDING_ABORTED;
+    }
+
+    //
+    // no need to prefetch a document that must be requested fresh each
+    // and every time.
+    //
+    uint32_t expTime;
+    if (NS_SUCCEEDED(cacheInfoChannel->GetCacheTokenExpirationTime(&expTime))) {
+        if (NowInSeconds() >= expTime) {
+            LOG(("document cannot be reused from cache; "
+                 "canceling prefetch\n"));
+            return NS_BINDING_ABORTED;
+        }
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPrefetchNode::OnDataAvailable(nsIRequest *aRequest,
+                                nsISupports *aContext,
+                                nsIInputStream *aStream,
+                                uint64_t aOffset,
+                                uint32_t aCount)
+{
+    uint32_t bytesRead = 0;
+    aStream->ReadSegments(NS_DiscardSegment, nullptr, aCount, &bytesRead);
+    mBytesRead += bytesRead;
+    LOG(("prefetched %u bytes [offset=%llu]\n", bytesRead, aOffset));
+    return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsPrefetchNode::OnStopRequest(nsIRequest *aRequest,
+                              nsISupports *aContext,
+                              nsresult aStatus)
+{
+    LOG(("done prefetching [status=%x]\n", aStatus));
+
+    if (mBytesRead == 0 && aStatus == NS_OK && mChannel) {
+        // we didn't need to read (because LOAD_ONLY_IF_MODIFIED was
+        // specified), but the object should report loadedSize as if it
+        // did.
+        mChannel->GetContentLength(&mBytesRead);
+    }
+
+    mService->NotifyLoadCompleted(this);
+    mService->DispatchEvent(this, mShouldFireLoadEvent || NS_SUCCEEDED(aStatus));
+    mService->ProcessNextURI(this);
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchNode::nsIInterfaceRequestor
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsPrefetchNode::GetInterface(const nsIID &aIID, void **aResult)
+{
+    if (aIID.Equals(NS_GET_IID(nsIChannelEventSink))) {
+        NS_ADDREF_THIS();
+        *aResult = static_cast<nsIChannelEventSink *>(this);
+        return NS_OK;
+    }
+
+    if (aIID.Equals(NS_GET_IID(nsIRedirectResultListener))) {
+        NS_ADDREF_THIS();
+        *aResult = static_cast<nsIRedirectResultListener *>(this);
+        return NS_OK;
+    }
+
+    return NS_ERROR_NO_INTERFACE;
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchNode::nsIChannelEventSink
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsPrefetchNode::AsyncOnChannelRedirect(nsIChannel *aOldChannel,
+                                       nsIChannel *aNewChannel,
+                                       uint32_t aFlags,
+                                       nsIAsyncVerifyRedirectCallback *callback)
+{
+    nsCOMPtr<nsIURI> newURI;
+    nsresult rv = aNewChannel->GetURI(getter_AddRefs(newURI));
+    if (NS_FAILED(rv))
+        return rv;
+
+    bool match;
+    rv = newURI->SchemeIs("http", &match); 
+    if (NS_FAILED(rv) || !match) {
+        rv = newURI->SchemeIs("https", &match); 
+        if (NS_FAILED(rv) || !match) {
+            LOG(("rejected: URL is not of type http/https\n"));
+            return NS_ERROR_ABORT;
+        }
+    }
+
+    // HTTP request headers are not automatically forwarded to the new channel.
+    nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aNewChannel);
+    NS_ENSURE_STATE(httpChannel);
+
+    httpChannel->SetRequestHeader(NS_LITERAL_CSTRING("X-Moz"),
+                                  NS_LITERAL_CSTRING("prefetch"),
+                                  false);
+
+    // Assign to mChannel after we get notification about success of the
+    // redirect in OnRedirectResult.
+    mRedirectChannel = aNewChannel;
+
+    callback->OnRedirectVerifyCallback(NS_OK);
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchNode::nsIRedirectResultListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsPrefetchNode::OnRedirectResult(bool proceeding)
+{
+    if (proceeding && mRedirectChannel)
+        mChannel = mRedirectChannel;
+
+    mRedirectChannel = nullptr;
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchService <public>
+//-----------------------------------------------------------------------------
+
+nsPrefetchService::nsPrefetchService()
+    : mMaxParallelism(6)
+    , mStopCount(0)
+    , mHaveProcessed(false)
+    , mDisabled(true)
+    , mAggressive(false)
+{
+}
+
+nsPrefetchService::~nsPrefetchService()
+{
+    Preferences::RemoveObserver(this, PREFETCH_PREF);
+    Preferences::RemoveObserver(this, PARALLELISM_PREF);
+    Preferences::RemoveObserver(this, AGGRESSIVE_PREF);
+    // cannot reach destructor if prefetch in progress (listener owns reference
+    // to this service)
+    EmptyQueue();
+}
+
+nsresult
+nsPrefetchService::Init()
+{
+    nsresult rv;
+
+    // read prefs and hook up pref observer
+    mDisabled = !Preferences::GetBool(PREFETCH_PREF, !mDisabled);
+    Preferences::AddWeakObserver(this, PREFETCH_PREF);
+
+    mMaxParallelism = Preferences::GetInt(PARALLELISM_PREF, mMaxParallelism);
+    if (mMaxParallelism < 1) {
+        mMaxParallelism = 1;
+    }
+    Preferences::AddWeakObserver(this, PARALLELISM_PREF);
+
+    mAggressive = Preferences::GetBool(AGGRESSIVE_PREF, false);
+    Preferences::AddWeakObserver(this, AGGRESSIVE_PREF);
+
+    // Observe xpcom-shutdown event
+    nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+    if (!observerService)
+      return NS_ERROR_FAILURE;
+
+    rv = observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, true);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!mDisabled)
+        AddProgressListener();
+
+    return NS_OK;
+}
+
+void
+nsPrefetchService::ProcessNextURI(nsPrefetchNode *aFinished)
+{
+    nsresult rv;
+
+    if (aFinished) {
+        mCurrentNodes.RemoveElement(aFinished);
+    }
+
+    if (mCurrentNodes.Length() >= static_cast<uint32_t>(mMaxParallelism)) {
+        // We already have enough prefetches going on, so hold off
+        // for now.
+        return;
+    }
+
+    do {
+        if (mQueue.empty()) {
+          break;
+        }
+        RefPtr<nsPrefetchNode> node = mQueue.front().forget();
+        mQueue.pop_front();
+
+        if (LOG_ENABLED()) {
+            LOG(("ProcessNextURI [%s]\n",
+                 node->mURI->GetSpecOrDefault().get())); }
+
+        //
+        // if opening the channel fails (e.g. security check returns an error),
+        // send an error event and then just skip to the next uri
+        //
+        rv = node->OpenChannel();
+        if (NS_SUCCEEDED(rv)) {
+            mCurrentNodes.AppendElement(node);
+        } else {
+          DispatchEvent(node, false);
+        }
+    }
+    while (NS_FAILED(rv));
+}
+
+void
+nsPrefetchService::NotifyLoadRequested(nsPrefetchNode *node)
+{
+    nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+    if (!observerService)
+      return;
+
+    observerService->NotifyObservers(static_cast<nsIStreamListener*>(node),
+                                     "prefetch-load-requested", nullptr);
+}
+
+void
+nsPrefetchService::NotifyLoadCompleted(nsPrefetchNode *node)
+{
+    nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+    if (!observerService)
+      return;
+
+    observerService->NotifyObservers(static_cast<nsIStreamListener*>(node),
+                                     "prefetch-load-completed", nullptr);
+}
+
+void
+nsPrefetchService::DispatchEvent(nsPrefetchNode *node, bool aSuccess)
+{
+    for (uint32_t i = 0; i < node->mSources.Length(); i++) {
+      nsCOMPtr<nsINode> domNode = do_QueryReferent(node->mSources.ElementAt(i));
+      if (domNode && domNode->IsInComposedDoc()) {
+        nsContentUtils::DispatchTrustedEvent(domNode->OwnerDoc(),
+                                             domNode,
+                                             aSuccess ?
+                                              NS_LITERAL_STRING("load") :
+                                              NS_LITERAL_STRING("error"),
+                                             /* aCanBubble = */ false,
+                                             /* aCancelable = */ false);
+      }
+    }
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchService <private>
+//-----------------------------------------------------------------------------
+
+void
+nsPrefetchService::AddProgressListener()
+{
+    // Register as an observer for the document loader  
+    nsCOMPtr<nsIWebProgress> progress = 
+        do_GetService(NS_DOCUMENTLOADER_SERVICE_CONTRACTID);
+    if (progress)
+        progress->AddProgressListener(this, nsIWebProgress::NOTIFY_STATE_DOCUMENT);
+}
+
+void
+nsPrefetchService::RemoveProgressListener()
+{
+    // Register as an observer for the document loader  
+    nsCOMPtr<nsIWebProgress> progress =
+        do_GetService(NS_DOCUMENTLOADER_SERVICE_CONTRACTID);
+    if (progress)
+        progress->RemoveProgressListener(this);
+}
+
+nsresult
+nsPrefetchService::EnqueueURI(nsIURI *aURI,
+                              nsIURI *aReferrerURI,
+                              nsIDOMNode *aSource,
+                              nsPrefetchNode **aNode)
+{
+    RefPtr<nsPrefetchNode> node = new nsPrefetchNode(this, aURI, aReferrerURI,
+                                                     aSource);
+    mQueue.push_back(node);
+    node.forget(aNode);
+    return NS_OK;
+}
+
+void
+nsPrefetchService::EmptyQueue()
+{
+    while (!mQueue.empty()) {
+        mQueue.pop_back();
+    }
+}
+
+void
+nsPrefetchService::StartPrefetching()
+{
+    //
+    // at initialization time we might miss the first DOCUMENT START
+    // notification, so we have to be careful to avoid letting our
+    // stop count go negative.
+    //
+    if (mStopCount > 0)
+        mStopCount--;
+
+    LOG(("StartPrefetching [stopcount=%d]\n", mStopCount));
+
+    // only start prefetching after we've received enough DOCUMENT
+    // STOP notifications.  we do this inorder to defer prefetching
+    // until after all sub-frames have finished loading.
+    if (!mStopCount) {
+        mHaveProcessed = true;
+        while (!mQueue.empty() && mCurrentNodes.Length() < static_cast<uint32_t>(mMaxParallelism)) {
+            ProcessNextURI(nullptr);
+        }
+    }
+}
+
+void
+nsPrefetchService::StopPrefetching()
+{
+    mStopCount++;
+
+    LOG(("StopPrefetching [stopcount=%d]\n", mStopCount));
+
+    // only kill the prefetch queue if we are actively prefetching right now
+    if (mCurrentNodes.IsEmpty()) {
+        return;
+    }
+
+    for (uint32_t i = 0; i < mCurrentNodes.Length(); ++i) {
+        mCurrentNodes[i]->CancelChannel(NS_BINDING_ABORTED);
+    }
+    mCurrentNodes.Clear();
+    EmptyQueue();
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchService::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsPrefetchService,
+                  nsIPrefetchService,
+                  nsIWebProgressListener,
+                  nsIObserver,
+                  nsISupportsWeakReference)
+
+//-----------------------------------------------------------------------------
+// nsPrefetchService::nsIPrefetchService
+//-----------------------------------------------------------------------------
+
+nsresult
+nsPrefetchService::Prefetch(nsIURI *aURI,
+                            nsIURI *aReferrerURI,
+                            nsIDOMNode *aSource,
+                            bool aExplicit)
+{
+    nsresult rv;
+
+    NS_ENSURE_ARG_POINTER(aURI);
+    NS_ENSURE_ARG_POINTER(aReferrerURI);
+
+    if (LOG_ENABLED()) {
+        LOG(("PrefetchURI [%s]\n", aURI->GetSpecOrDefault().get()));
+    }
+
+    if (mDisabled) {
+        LOG(("rejected: prefetch service is disabled\n"));
+        return NS_ERROR_ABORT;
+    }
+
+    //
+    // XXX we should really be asking the protocol handler if it supports
+    // caching, so we can determine if there is any value to prefetching.
+    // for now, we'll only prefetch http links since we know that's the 
+    // most common case.  ignore https links since https content only goes
+    // into the memory cache.
+    //
+    // XXX we might want to either leverage nsIProtocolHandler::protocolFlags
+    // or possibly nsIRequest::loadFlags to determine if this URI should be
+    // prefetched.
+    //
+    bool match;
+    rv = aURI->SchemeIs("http", &match); 
+    if (NS_FAILED(rv) || !match) {
+        rv = aURI->SchemeIs("https", &match); 
+        if (NS_FAILED(rv) || !match) {
+            LOG(("rejected: URL is not of type http/https\n"));
+            return NS_ERROR_ABORT;
+        }
+    }
+
+    // 
+    // the referrer URI must be http:
+    //
+    rv = aReferrerURI->SchemeIs("http", &match);
+    if (NS_FAILED(rv) || !match) {
+        rv = aReferrerURI->SchemeIs("https", &match);
+        if (NS_FAILED(rv) || !match) {
+            LOG(("rejected: referrer URL is neither http nor https\n"));
+            return NS_ERROR_ABORT;
+        }
+    }
+
+    // skip URLs that contain query strings, except URLs for which prefetching
+    // has been explicitly requested.
+    if (!aExplicit) {
+        nsCOMPtr<nsIURL> url(do_QueryInterface(aURI, &rv));
+        if (NS_FAILED(rv)) return rv;
+        nsAutoCString query;
+        rv = url->GetQuery(query);
+        if (NS_FAILED(rv) || !query.IsEmpty()) {
+            LOG(("rejected: URL has a query string\n"));
+            return NS_ERROR_ABORT;
+        }
+    }
+
+    //
+    // Check whether it is being prefetched.
+    //
+    for (uint32_t i = 0; i < mCurrentNodes.Length(); ++i) {
+        bool equals;
+        if (NS_SUCCEEDED(mCurrentNodes[i]->mURI->Equals(aURI, &equals)) &&
+            equals) {
+            nsCOMPtr<nsIWeakReference> source = do_GetWeakReference(aSource);
+            if (mCurrentNodes[i]->mSources.IndexOf(source) ==
+                mCurrentNodes[i]->mSources.NoIndex) {
+                LOG(("URL is already being prefetched, add a new reference "
+                     "document\n"));
+                mCurrentNodes[i]->mSources.AppendElement(source);
+                return NS_OK;
+            } else {
+                LOG(("URL is already being prefetched by this document"));
+                return NS_ERROR_ABORT;
+            }
+        }
+    }
+
+    //
+    // Check whether it is on the prefetch queue.
+    //
+    for (std::deque<RefPtr<nsPrefetchNode>>::iterator nodeIt = mQueue.begin();
+         nodeIt != mQueue.end(); nodeIt++) {
+        bool equals;
+        RefPtr<nsPrefetchNode> node = nodeIt->get();
+        if (NS_SUCCEEDED(node->mURI->Equals(aURI, &equals)) && equals) {
+            nsCOMPtr<nsIWeakReference> source = do_GetWeakReference(aSource);
+            if (node->mSources.IndexOf(source) ==
+                node->mSources.NoIndex) {
+                LOG(("URL is already being prefetched, add a new reference "
+                     "document\n"));
+                node->mSources.AppendElement(do_GetWeakReference(aSource));
+                return NS_OK;
+            } else {
+                LOG(("URL is already being prefetched by this document"));
+                return NS_ERROR_ABORT;
+            }
+     
+        }
+    }
+
+    RefPtr<nsPrefetchNode> enqueuedNode;
+    rv = EnqueueURI(aURI, aReferrerURI, aSource,
+                    getter_AddRefs(enqueuedNode));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    NotifyLoadRequested(enqueuedNode);
+
+    // if there are no pages loading, kick off the request immediately
+    if (mStopCount == 0 && mHaveProcessed) {
+        ProcessNextURI(nullptr);
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPrefetchService::CancelPrefetchURI(nsIURI* aURI,
+                                     nsIDOMNode* aSource)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    if (LOG_ENABLED()) {
+        LOG(("CancelPrefetchURI [%s]\n", aURI->GetSpecOrDefault().get()));
+    }
+
+    //
+    // look in current prefetches
+    //
+    for (uint32_t i = 0; i < mCurrentNodes.Length(); ++i) {
+        bool equals;
+        if (NS_SUCCEEDED(mCurrentNodes[i]->mURI->Equals(aURI, &equals)) &&
+            equals) {
+            nsCOMPtr<nsIWeakReference> source = do_GetWeakReference(aSource);
+            if (mCurrentNodes[i]->mSources.IndexOf(source) !=
+                mCurrentNodes[i]->mSources.NoIndex) {
+                mCurrentNodes[i]->mSources.RemoveElement(source);
+                if (mCurrentNodes[i]->mSources.IsEmpty()) {
+                    mCurrentNodes[i]->CancelChannel(NS_BINDING_ABORTED);
+                    mCurrentNodes.RemoveElementAt(i);
+                }
+                return NS_OK;
+            }
+            return NS_ERROR_FAILURE;
+        }
+    }
+
+    //
+    // look into the prefetch queue
+    //
+    for (std::deque<RefPtr<nsPrefetchNode>>::iterator nodeIt = mQueue.begin();
+         nodeIt != mQueue.end(); nodeIt++) {
+        bool equals;
+        RefPtr<nsPrefetchNode> node = nodeIt->get();
+        if (NS_SUCCEEDED(node->mURI->Equals(aURI, &equals)) && equals) {
+            nsCOMPtr<nsIWeakReference> source = do_GetWeakReference(aSource);
+            if (node->mSources.IndexOf(source) !=
+                node->mSources.NoIndex) {
+
+#ifdef DEBUG
+                int32_t inx = node->mSources.IndexOf(source);
+                nsCOMPtr<nsIDOMNode> domNode =
+                    do_QueryReferent(node->mSources.ElementAt(inx));
+                MOZ_ASSERT(domNode);
+#endif
+
+                node->mSources.RemoveElement(source);
+                if (node->mSources.IsEmpty()) {
+                    mQueue.erase(nodeIt);
+                }
+                return NS_OK;
+            }
+            return NS_ERROR_FAILURE;
+        }
+    }
+
+    // not found!
+    return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsPrefetchService::PrefetchURI(nsIURI *aURI,
+                               nsIURI *aReferrerURI,
+                               nsIDOMNode *aSource,
+                               bool aExplicit)
+{
+    return Prefetch(aURI, aReferrerURI, aSource, aExplicit);
+}
+
+NS_IMETHODIMP
+nsPrefetchService::HasMoreElements(bool *aHasMore)
+{
+    *aHasMore = (mCurrentNodes.Length() || !mQueue.empty());
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchService::nsIWebProgressListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsPrefetchService::OnProgressChange(nsIWebProgress *aProgress,
+                                  nsIRequest *aRequest, 
+                                  int32_t curSelfProgress, 
+                                  int32_t maxSelfProgress, 
+                                  int32_t curTotalProgress, 
+                                  int32_t maxTotalProgress)
+{
+    NS_NOTREACHED("notification excluded in AddProgressListener(...)");
+    return NS_OK;
+}
+
+NS_IMETHODIMP 
+nsPrefetchService::OnStateChange(nsIWebProgress* aWebProgress, 
+                                 nsIRequest *aRequest, 
+                                 uint32_t progressStateFlags, 
+                                 nsresult aStatus)
+{
+    if (mAggressive) {
+        LOG(("Document load state is ignored in aggressive mode"));
+        return NS_OK;
+    }
+
+    if (progressStateFlags & STATE_IS_DOCUMENT) {
+        if (progressStateFlags & STATE_STOP)
+            StartPrefetching();
+        else if (progressStateFlags & STATE_START)
+            StopPrefetching();
+    }
+            
+    return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsPrefetchService::OnLocationChange(nsIWebProgress* aWebProgress,
+                                    nsIRequest* aRequest,
+                                    nsIURI *location,
+                                    uint32_t aFlags)
+{
+    NS_NOTREACHED("notification excluded in AddProgressListener(...)");
+    return NS_OK;
+}
+
+NS_IMETHODIMP 
+nsPrefetchService::OnStatusChange(nsIWebProgress* aWebProgress,
+                                  nsIRequest* aRequest,
+                                  nsresult aStatus,
+                                  const char16_t* aMessage)
+{
+    NS_NOTREACHED("notification excluded in AddProgressListener(...)");
+    return NS_OK;
+}
+
+NS_IMETHODIMP 
+nsPrefetchService::OnSecurityChange(nsIWebProgress *aWebProgress, 
+                                    nsIRequest *aRequest, 
+                                    uint32_t state)
+{
+    NS_NOTREACHED("notification excluded in AddProgressListener(...)");
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsPrefetchService::nsIObserver
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsPrefetchService::Observe(nsISupports     *aSubject,
+                           const char      *aTopic,
+                           const char16_t *aData)
+{
+    LOG(("nsPrefetchService::Observe [topic=%s]\n", aTopic));
+
+    if (!strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+        StopPrefetching();
+        EmptyQueue();
+        mDisabled = true;
+    }
+    else if (!strcmp(aTopic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID)) {
+        const nsCString converted = NS_ConvertUTF16toUTF8(aData);
+        const char* pref = converted.get();
+        if (!strcmp(pref, PREFETCH_PREF)) {
+            if (Preferences::GetBool(PREFETCH_PREF, false)) {
+                if (mDisabled) {
+                    LOG(("enabling prefetching\n"));
+                    mDisabled = false;
+                    AddProgressListener();
+                }
+            } else {
+                if (!mDisabled) {
+                    LOG(("disabling prefetching\n"));
+                    StopPrefetching();
+                    EmptyQueue();
+                    mDisabled = true;
+                    RemoveProgressListener();
+                }
+            }
+        } else if (!strcmp(pref, PARALLELISM_PREF)) {
+            mMaxParallelism = Preferences::GetInt(PARALLELISM_PREF, mMaxParallelism);
+            if (mMaxParallelism < 1) {
+                mMaxParallelism = 1;
+            }
+            // If our parallelism has increased, go ahead and kick off enough
+            // prefetches to fill up our allowance. If we're now over our
+            // allowance, we'll just silently let some of them finish to get
+            // back below our limit.
+            while (!mQueue.empty() && mCurrentNodes.Length() < static_cast<uint32_t>(mMaxParallelism)) {
+                ProcessNextURI(nullptr);
+            }
+        } else if (!strcmp(pref, AGGRESSIVE_PREF)) {
+          mAggressive = Preferences::GetBool(AGGRESSIVE_PREF, false);
+          // in aggressive mode, clear stop count and start prefetching immediately
+          if (mAggressive) {
+            mStopCount = 0;
+            StartPrefetching();
+          }
+        }
+    }
+
+    return NS_OK;
+}
+
+// vim: ts=4 sw=4 expandtab
diff --git a/uriloader/prefetch/nsPrefetchService.h b/uriloader/prefetch/nsPrefetchService.h
new file mode 100644
index 0000000000..883449e689
--- /dev/null
+++ b/uriloader/prefetch/nsPrefetchService.h
@@ -0,0 +1,121 @@
+/* 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/. */
+
+#ifndef nsPrefetchService_h__
+#define nsPrefetchService_h__
+
+#include "nsCPrefetchService.h"
+#include "nsIObserver.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIChannelEventSink.h"
+#include "nsIRedirectResultListener.h"
+#include "nsIWebProgressListener.h"
+#include "nsIStreamListener.h"
+#include "nsIChannel.h"
+#include "nsIURI.h"
+#include "nsWeakReference.h"
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+#include "mozilla/Attributes.h"
+#include <deque>
+
+class nsPrefetchService;
+class nsPrefetchNode;
+
+//-----------------------------------------------------------------------------
+// nsPrefetchService
+//-----------------------------------------------------------------------------
+
+class nsPrefetchService final : public nsIPrefetchService
+                              , public nsIWebProgressListener
+                              , public nsIObserver
+                              , public nsSupportsWeakReference
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIPREFETCHSERVICE
+    NS_DECL_NSIWEBPROGRESSLISTENER
+    NS_DECL_NSIOBSERVER
+
+    nsPrefetchService();
+
+    nsresult Init();
+    void     ProcessNextURI(nsPrefetchNode *aFinished);
+
+    void NotifyLoadRequested(nsPrefetchNode *node);
+    void NotifyLoadCompleted(nsPrefetchNode *node);
+    void DispatchEvent(nsPrefetchNode *node, bool aSuccess);
+
+private:
+    ~nsPrefetchService();
+
+    nsresult Prefetch(nsIURI *aURI,
+                      nsIURI *aReferrerURI,
+                      nsIDOMNode *aSource,
+                      bool aExplicit);
+
+    void     AddProgressListener();
+    void     RemoveProgressListener();
+    nsresult EnqueueURI(nsIURI *aURI, nsIURI *aReferrerURI,
+                        nsIDOMNode *aSource, nsPrefetchNode **node);
+    void     EmptyQueue();
+
+    void     StartPrefetching();
+    void     StopPrefetching();
+
+    std::deque<RefPtr<nsPrefetchNode>> mQueue;
+    nsTArray<RefPtr<nsPrefetchNode>>   mCurrentNodes;
+    int32_t                            mMaxParallelism;
+    int32_t                            mStopCount;
+    // true if pending document loads have ever reached zero.
+    int32_t                            mHaveProcessed;
+    bool                               mDisabled;
+
+    // In usual case prefetch does not start until all normal loads are done.
+    // Aggressive mode ignores normal loads and just start prefetch ASAP.
+    // It's mainly for testing purpose and discoraged for normal use;
+    // see https://bugzilla.mozilla.org/show_bug.cgi?id=1281415 for details.
+    bool                               mAggressive;
+};
+
+//-----------------------------------------------------------------------------
+// nsPrefetchNode
+//-----------------------------------------------------------------------------
+
+class nsPrefetchNode final : public nsIStreamListener
+                           , public nsIInterfaceRequestor
+                           , public nsIChannelEventSink
+                           , public nsIRedirectResultListener
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIREQUESTOBSERVER
+    NS_DECL_NSISTREAMLISTENER
+    NS_DECL_NSIINTERFACEREQUESTOR
+    NS_DECL_NSICHANNELEVENTSINK
+    NS_DECL_NSIREDIRECTRESULTLISTENER
+
+    nsPrefetchNode(nsPrefetchService *aPrefetchService,
+                   nsIURI *aURI,
+                   nsIURI *aReferrerURI,
+                   nsIDOMNode *aSource);
+
+    nsresult OpenChannel();
+    nsresult CancelChannel(nsresult error);
+
+    nsCOMPtr<nsIURI>                      mURI;
+    nsCOMPtr<nsIURI>                      mReferrerURI;
+    nsTArray<nsCOMPtr<nsIWeakReference>>  mSources;
+
+private:
+    ~nsPrefetchNode() {}
+
+    RefPtr<nsPrefetchService>   mService;
+    nsCOMPtr<nsIChannel>        mChannel;
+    nsCOMPtr<nsIChannel>        mRedirectChannel;
+    int64_t                     mBytesRead;
+    bool                        mShouldFireLoadEvent;
+};
+
+#endif // !nsPrefetchService_h__