Add m-esr52 at 52.6.0

11 files changed, 2238 insertions, 0 deletions

diff --git a/netwerk/protocol/about/moz.build b/netwerk/protocol/about/moz.build
new file mode 100644
index 0000000000..60a10c9cc7
--- /dev/null
+++ b/netwerk/protocol/about/moz.build
@@ -0,0 +1,34 @@
+# -*- 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 += [
+    'nsIAboutModule.idl',
+]
+
+XPIDL_MODULE = 'necko_about'
+
+EXPORTS += [
+    'nsAboutProtocolUtils.h',
+]
+
+UNIFIED_SOURCES += [
+    'nsAboutBlank.cpp',
+    'nsAboutCache.cpp',
+    'nsAboutCacheEntry.cpp',
+    'nsAboutProtocolHandler.cpp',
+]
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+FINAL_LIBRARY = 'xul'
+
+LOCAL_INCLUDES += [
+    '/netwerk/base',
+    '/netwerk/cache2',
+]
+
+if CONFIG['GNU_CXX']:
+    CXXFLAGS += ['-Wno-error=shadow']
diff --git a/netwerk/protocol/about/nsAboutBlank.cpp b/netwerk/protocol/about/nsAboutBlank.cpp
new file mode 100644
index 0000000000..be10be9ac7
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutBlank.cpp
@@ -0,0 +1,59 @@
+/* -*- Mode: C++; tab-width: 2; 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 "nsAboutBlank.h"
+#include "nsStringStream.h"
+#include "nsNetUtil.h"
+#include "nsContentUtils.h"
+
+NS_IMPL_ISUPPORTS(nsAboutBlank, nsIAboutModule)
+
+NS_IMETHODIMP
+nsAboutBlank::NewChannel(nsIURI* aURI,
+                         nsILoadInfo* aLoadInfo,
+                         nsIChannel** result)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    nsCOMPtr<nsIInputStream> in;
+    nsresult rv = NS_NewCStringInputStream(getter_AddRefs(in), EmptyCString());
+    if (NS_FAILED(rv)) return rv;
+
+    nsCOMPtr<nsIChannel> channel;
+    rv = NS_NewInputStreamChannelInternal(getter_AddRefs(channel),
+                                          aURI,
+                                          in,
+                                          NS_LITERAL_CSTRING("text/html"),
+                                          NS_LITERAL_CSTRING("utf-8"),
+                                          aLoadInfo);
+    if (NS_FAILED(rv)) return rv;
+
+    channel.forget(result);
+    return rv;
+}
+
+NS_IMETHODIMP
+nsAboutBlank::GetURIFlags(nsIURI *aURI, uint32_t *result)
+{
+    *result = nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT |
+              nsIAboutModule::URI_CAN_LOAD_IN_CHILD |
+              nsIAboutModule::MAKE_LINKABLE |
+              nsIAboutModule::HIDE_FROM_ABOUTABOUT;
+    return NS_OK;
+}
+
+nsresult
+nsAboutBlank::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
+{
+    nsAboutBlank* about = new nsAboutBlank();
+    if (about == nullptr)
+        return NS_ERROR_OUT_OF_MEMORY;
+    NS_ADDREF(about);
+    nsresult rv = about->QueryInterface(aIID, aResult);
+    NS_RELEASE(about);
+    return rv;
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/netwerk/protocol/about/nsAboutBlank.h b/netwerk/protocol/about/nsAboutBlank.h
new file mode 100644
index 0000000000..aae6e072d6
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutBlank.h
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 2; 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 nsAboutBlank_h__
+#define nsAboutBlank_h__
+
+#include "nsIAboutModule.h"
+
+class nsAboutBlank : public nsIAboutModule 
+{
+public:
+    NS_DECL_ISUPPORTS
+
+    NS_DECL_NSIABOUTMODULE
+
+    nsAboutBlank() {}
+
+    static nsresult
+    Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
+
+private:
+    virtual ~nsAboutBlank() {}
+};
+
+#define NS_ABOUT_BLANK_MODULE_CID                    \
+{ /* 3decd6c8-30ef-11d3-8cd0-0060b0fc14a3 */         \
+    0x3decd6c8,                                      \
+    0x30ef,                                          \
+    0x11d3,                                          \
+    {0x8c, 0xd0, 0x00, 0x60, 0xb0, 0xfc, 0x14, 0xa3} \
+}
+
+#endif // nsAboutBlank_h__
diff --git a/netwerk/protocol/about/nsAboutCache.cpp b/netwerk/protocol/about/nsAboutCache.cpp
new file mode 100644
index 0000000000..2eb5e3b42e
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutCache.cpp
@@ -0,0 +1,585 @@
+/* -*- Mode: C++; tab-width: 2; 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 "nsAboutCache.h"
+#include "nsIInputStream.h"
+#include "nsIStorageStream.h"
+#include "nsIURI.h"
+#include "nsCOMPtr.h"
+#include "nsNetUtil.h"
+#include "nsIPipe.h"
+#include "nsContentUtils.h"
+#include "nsEscape.h"
+#include "nsAboutProtocolUtils.h"
+#include "nsPrintfCString.h"
+
+#include "nsICacheStorageService.h"
+#include "nsICacheStorage.h"
+#include "CacheFileUtils.h"
+#include "CacheObserver.h"
+
+#include "nsThreadUtils.h"
+
+using namespace mozilla::net;
+
+NS_IMPL_ISUPPORTS(nsAboutCache, nsIAboutModule)
+NS_IMPL_ISUPPORTS(nsAboutCache::Channel, nsIChannel, nsIRequest, nsICacheStorageVisitor)
+
+NS_IMETHODIMP
+nsAboutCache::NewChannel(nsIURI* aURI,
+                         nsILoadInfo* aLoadInfo,
+                         nsIChannel** result)
+{
+    nsresult rv;
+
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    RefPtr<Channel> channel = new Channel();
+    rv = channel->Init(aURI, aLoadInfo);
+    if (NS_FAILED(rv)) return rv;
+
+    channel.forget(result);
+
+    return NS_OK;
+}
+
+nsresult
+nsAboutCache::Channel::Init(nsIURI* aURI, nsILoadInfo* aLoadInfo)
+{
+    nsresult rv;
+
+    mCancel = false;
+
+    nsCOMPtr<nsIInputStream> inputStream;
+    rv = NS_NewPipe(getter_AddRefs(inputStream), getter_AddRefs(mStream),
+                    16384, (uint32_t)-1,
+                    true, // non-blocking input
+                    false // blocking output
+    );
+    if (NS_FAILED(rv)) return rv;
+
+    nsAutoCString storageName;
+    rv = ParseURI(aURI, storageName);
+    if (NS_FAILED(rv)) return rv;
+
+    mOverview = storageName.IsEmpty();
+    if (mOverview) {
+        // ...and visit all we can
+        mStorageList.AppendElement(NS_LITERAL_CSTRING("memory"));
+        mStorageList.AppendElement(NS_LITERAL_CSTRING("disk"));
+        mStorageList.AppendElement(NS_LITERAL_CSTRING("appcache"));
+    } else {
+        // ...and visit just the specified storage, entries will output too
+        mStorageList.AppendElement(storageName);
+    }
+
+    // The entries header is added on encounter of the first entry
+    mEntriesHeaderAdded = false;
+
+    rv = NS_NewInputStreamChannelInternal(getter_AddRefs(mChannel),
+                                          aURI,
+                                          inputStream,
+                                          NS_LITERAL_CSTRING("text/html"),
+                                          NS_LITERAL_CSTRING("utf-8"),
+                                          aLoadInfo);
+    if (NS_FAILED(rv)) return rv;
+
+    mBuffer.AssignLiteral(
+        "<!DOCTYPE html>\n"
+        "<html>\n"
+        "<head>\n"
+        "  <title>Network Cache Storage Information</title>\n"
+        "  <meta charset=\"utf-8\">\n"
+        "  <link rel=\"stylesheet\" href=\"chrome://global/skin/about.css\"/>\n"
+        "  <link rel=\"stylesheet\" href=\"chrome://global/skin/aboutCache.css\"/>\n"
+        "  <script src=\"chrome://global/content/aboutCache.js\"></script>"
+        "</head>\n"
+        "<body class=\"aboutPageWideContainer\">\n"
+        "<h1>Information about the Network Cache Storage Service</h1>\n");
+
+    // Add the context switch controls
+    mBuffer.AppendLiteral(
+        "<label><input id='priv' type='checkbox'/> Private</label>\n"
+        "<label><input id='anon' type='checkbox'/> Anonymous</label>\n"
+    );
+
+    if (CacheObserver::UseNewCache()) {
+        // Visit scoping by browser and appid is not implemented for
+        // the old cache, simply don't add these controls.
+        // The appid/inbrowser entries are already mixed in the default
+        // view anyway.
+        mBuffer.AppendLiteral(
+            "<label><input id='appid' type='text' size='6'/> AppID</label>\n"
+            "<label><input id='inbrowser' type='checkbox'/> In Browser Element</label>\n"
+        );
+    }
+
+    mBuffer.AppendLiteral(
+        "<label><input id='submit' type='button' value='Update' onclick='navigate()'/></label>\n"
+    );
+
+    if (!mOverview) {
+        mBuffer.AppendLiteral("<a href=\"about:cache?storage=&amp;context=");
+        char* escapedContext = nsEscapeHTML(mContextString.get());
+        mBuffer.Append(escapedContext);
+        free(escapedContext);
+        mBuffer.AppendLiteral("\">Back to overview</a>");
+    }
+
+    rv = FlushBuffer();
+    if (NS_FAILED(rv)) {
+        NS_WARNING("Failed to flush buffer");
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsAboutCache::Channel::AsyncOpen(nsIStreamListener *aListener, nsISupports *aContext)
+{
+    nsresult rv;
+
+    if (!mChannel) {
+        return NS_ERROR_UNEXPECTED;
+    }
+
+    // Kick the walk loop.
+    rv = VisitNextStorage();
+    if (NS_FAILED(rv)) return rv;
+
+    MOZ_ASSERT(!aContext, "asyncOpen2() does not take a context argument");
+    rv = NS_MaybeOpenChannelUsingAsyncOpen2(mChannel, aListener);
+    if (NS_FAILED(rv)) return rv;
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsAboutCache::Channel::AsyncOpen2(nsIStreamListener *aListener)
+{
+    return AsyncOpen(aListener, nullptr);
+}
+
+NS_IMETHODIMP nsAboutCache::Channel::Open(nsIInputStream * *_retval)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP nsAboutCache::Channel::Open2(nsIInputStream * *_retval)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult
+nsAboutCache::Channel::ParseURI(nsIURI * uri, nsACString & storage)
+{
+    //
+    // about:cache[?storage=<storage-name>[&context=<context-key>]]
+    //
+    nsresult rv;
+
+    nsAutoCString path;
+    rv = uri->GetPath(path);
+    if (NS_FAILED(rv)) return rv;
+
+    mContextString.Truncate();
+    mLoadInfo = CacheFileUtils::ParseKey(NS_LITERAL_CSTRING(""));
+    storage.Truncate();
+
+    nsACString::const_iterator start, valueStart, end;
+    path.BeginReading(start);
+    path.EndReading(end);
+
+    valueStart = end;
+    if (!FindInReadable(NS_LITERAL_CSTRING("?storage="), start, valueStart)) {
+        return NS_OK;
+    }
+
+    nsACString::const_iterator storageNameBegin = valueStart;
+
+    start = valueStart;
+    valueStart = end;
+    if (!FindInReadable(NS_LITERAL_CSTRING("&context="), start, valueStart))
+        start = end;
+
+    nsACString::const_iterator storageNameEnd = start;
+
+    mContextString = Substring(valueStart, end);
+    mLoadInfo = CacheFileUtils::ParseKey(mContextString);
+    storage.Assign(Substring(storageNameBegin, storageNameEnd));
+
+    return NS_OK;
+}
+
+nsresult
+nsAboutCache::Channel::VisitNextStorage()
+{
+    if (!mStorageList.Length())
+        return NS_ERROR_NOT_AVAILABLE;
+
+    mStorageName = mStorageList[0];
+    mStorageList.RemoveElementAt(0);
+
+    // Must re-dispatch since we cannot start another visit cycle
+    // from visitor callback.  The cache v1 service doesn't like it.
+    // TODO - mayhemer, bug 913828, remove this dispatch and call
+    // directly.
+    return NS_DispatchToMainThread(mozilla::NewRunnableMethod(this, &nsAboutCache::Channel::FireVisitStorage));
+}
+
+void
+nsAboutCache::Channel::FireVisitStorage()
+{
+    nsresult rv;
+
+    rv = VisitStorage(mStorageName);
+    if (NS_FAILED(rv)) {
+        if (mLoadInfo) {
+            char* escaped = nsEscapeHTML(mStorageName.get());
+            mBuffer.Append(
+                nsPrintfCString("<p>Unrecognized storage name '%s' in about:cache URL</p>",
+                                escaped));
+            free(escaped);
+        } else {
+            char* escaped = nsEscapeHTML(mContextString.get());
+            mBuffer.Append(
+                nsPrintfCString("<p>Unrecognized context key '%s' in about:cache URL</p>",
+                                escaped));
+            free(escaped);
+        }
+
+        rv = FlushBuffer();
+        if (NS_FAILED(rv)) {
+            NS_WARNING("Failed to flush buffer");
+        }
+
+        // Simulate finish of a visit cycle, this tries the next storage
+        // or closes the output stream (i.e. the UI loader will stop spinning)
+        OnCacheEntryVisitCompleted();
+    }
+}
+
+nsresult
+nsAboutCache::Channel::VisitStorage(nsACString const & storageName)
+{
+    nsresult rv;
+
+    rv = GetStorage(storageName, mLoadInfo, getter_AddRefs(mStorage));
+    if (NS_FAILED(rv)) return rv;
+
+    rv = mStorage->AsyncVisitStorage(this, !mOverview);
+    if (NS_FAILED(rv)) return rv;
+
+    return NS_OK;
+}
+
+//static
+nsresult
+nsAboutCache::GetStorage(nsACString const & storageName,
+                         nsILoadContextInfo* loadInfo,
+                         nsICacheStorage **storage)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsICacheStorageService> cacheService =
+             do_GetService("@mozilla.org/netwerk/cache-storage-service;1", &rv);
+    if (NS_FAILED(rv)) return rv;
+
+    nsCOMPtr<nsICacheStorage> cacheStorage;
+    if (storageName == "disk") {
+        rv = cacheService->DiskCacheStorage(
+            loadInfo, false, getter_AddRefs(cacheStorage));
+    } else if (storageName == "memory") {
+        rv = cacheService->MemoryCacheStorage(
+            loadInfo, getter_AddRefs(cacheStorage));
+    } else if (storageName == "appcache") {
+        rv = cacheService->AppCacheStorage(
+            loadInfo, nullptr, getter_AddRefs(cacheStorage));
+    } else {
+        rv = NS_ERROR_UNEXPECTED;
+    }
+    if (NS_FAILED(rv)) return rv;
+
+    cacheStorage.forget(storage);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutCache::Channel::OnCacheStorageInfo(uint32_t aEntryCount, uint64_t aConsumption,
+                                          uint64_t aCapacity, nsIFile * aDirectory)
+{
+    // We need mStream for this
+    if (!mStream) {
+        return NS_ERROR_FAILURE;
+    }
+
+    mBuffer.AssignLiteral("<h2>");
+    mBuffer.Append(mStorageName);
+    mBuffer.AppendLiteral("</h2>\n"
+                          "<table id=\"");
+    mBuffer.AppendLiteral("\">\n");
+
+    // Write out cache info
+    // Number of entries
+    mBuffer.AppendLiteral("  <tr>\n"
+                          "    <th>Number of entries:</th>\n"
+                          "    <td>");
+    mBuffer.AppendInt(aEntryCount);
+    mBuffer.AppendLiteral("</td>\n"
+                          "  </tr>\n");
+
+    // Maximum storage size
+    mBuffer.AppendLiteral("  <tr>\n"
+                          "    <th>Maximum storage size:</th>\n"
+                          "    <td>");
+    mBuffer.AppendInt(aCapacity / 1024);
+    mBuffer.AppendLiteral(" KiB</td>\n"
+                          "  </tr>\n");
+
+    // Storage in use
+    mBuffer.AppendLiteral("  <tr>\n"
+                          "    <th>Storage in use:</th>\n"
+                          "    <td>");
+    mBuffer.AppendInt(aConsumption / 1024);
+    mBuffer.AppendLiteral(" KiB</td>\n"
+                          "  </tr>\n");
+
+    // Storage disk location
+    mBuffer.AppendLiteral("  <tr>\n"
+                          "    <th>Storage disk location:</th>\n"
+                          "    <td>");
+    if (aDirectory) {
+        nsAutoString path;
+        aDirectory->GetPath(path);
+        mBuffer.Append(NS_ConvertUTF16toUTF8(path));
+    } else {
+        mBuffer.AppendLiteral("none, only stored in memory");
+    }
+    mBuffer.AppendLiteral("    </td>\n"
+                          "  </tr>\n");
+
+    if (mOverview) { // The about:cache case
+        if (aEntryCount != 0) { // Add the "List Cache Entries" link
+            mBuffer.AppendLiteral("  <tr>\n"
+                                  "    <th><a href=\"about:cache?storage=");
+            mBuffer.Append(mStorageName);
+            mBuffer.AppendLiteral("&amp;context=");
+            char* escapedContext = nsEscapeHTML(mContextString.get());
+            mBuffer.Append(escapedContext);
+            free(escapedContext);
+            mBuffer.AppendLiteral("\">List Cache Entries</a></th>\n"
+                                  "  </tr>\n");
+        }
+    }
+
+    mBuffer.AppendLiteral("</table>\n");
+
+    // The entries header is added on encounter of the first entry
+    mEntriesHeaderAdded = false;
+
+    nsresult rv = FlushBuffer();
+    if (NS_FAILED(rv)) {
+        NS_WARNING("Failed to flush buffer");
+    }
+
+    if (mOverview) {
+        // OnCacheEntryVisitCompleted() is not called when we do not iterate
+        // cache entries.  Since this moves forward to the next storage in
+        // the list we want to visit, artificially call it here.
+        OnCacheEntryVisitCompleted();
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutCache::Channel::OnCacheEntryInfo(nsIURI *aURI, const nsACString & aIdEnhance,
+                                        int64_t aDataSize, int32_t aFetchCount,
+                                        uint32_t aLastModified, uint32_t aExpirationTime,
+                                        bool aPinned)
+{
+    // We need mStream for this
+    if (!mStream || mCancel) {
+        // Returning a failure from this callback stops the iteration
+        return NS_ERROR_FAILURE;
+    }
+
+    if (!mEntriesHeaderAdded) {
+        mBuffer.AppendLiteral("<hr/>\n"
+                              "<table id=\"entries\">\n"
+                              "  <colgroup>\n"
+                              "   <col id=\"col-key\">\n"
+                              "   <col id=\"col-dataSize\">\n"
+                              "   <col id=\"col-fetchCount\">\n"
+                              "   <col id=\"col-lastModified\">\n"
+                              "   <col id=\"col-expires\">\n"
+                              "   <col id=\"col-pinned\">\n"
+                              "  </colgroup>\n"
+                              "  <thead>\n"
+                              "    <tr>\n"
+                              "      <th>Key</th>\n"
+                              "      <th>Data size</th>\n"
+                              "      <th>Fetch count</th>\n"
+                              "      <th>Last Modifed</th>\n"
+                              "      <th>Expires</th>\n"
+                              "      <th>Pinning</th>\n"
+                              "    </tr>\n"
+                              "  </thead>\n");
+        mEntriesHeaderAdded = true;
+    }
+
+    // Generate a about:cache-entry URL for this entry...
+
+    nsAutoCString url;
+    url.AssignLiteral("about:cache-entry?storage=");
+    url.Append(mStorageName);
+
+    url.AppendLiteral("&amp;context=");
+    char* escapedContext = nsEscapeHTML(mContextString.get());
+    url += escapedContext;
+    free(escapedContext);
+
+    url.AppendLiteral("&amp;eid=");
+    char* escapedEID = nsEscapeHTML(aIdEnhance.BeginReading());
+    url += escapedEID;
+    free(escapedEID);
+
+    nsAutoCString cacheUriSpec;
+    aURI->GetAsciiSpec(cacheUriSpec);
+    char* escapedCacheURI = nsEscapeHTML(cacheUriSpec.get());
+    url.AppendLiteral("&amp;uri=");
+    url += escapedCacheURI;
+
+    // Entry start...
+    mBuffer.AppendLiteral("  <tr>\n");
+
+    // URI
+    mBuffer.AppendLiteral("    <td><a href=\"");
+    mBuffer.Append(url);
+    mBuffer.AppendLiteral("\">");
+    if (!aIdEnhance.IsEmpty()) {
+        mBuffer.Append(aIdEnhance);
+        mBuffer.Append(':');
+    }
+    mBuffer.Append(escapedCacheURI);
+    mBuffer.AppendLiteral("</a></td>\n");
+
+    free(escapedCacheURI);
+
+    // Content length
+    mBuffer.AppendLiteral("    <td>");
+    mBuffer.AppendInt(aDataSize);
+    mBuffer.AppendLiteral(" bytes</td>\n");
+
+    // Number of accesses
+    mBuffer.AppendLiteral("    <td>");
+    mBuffer.AppendInt(aFetchCount);
+    mBuffer.AppendLiteral("</td>\n");
+
+    // vars for reporting time
+    char buf[255];
+
+    // Last modified time
+    mBuffer.AppendLiteral("    <td>");
+    if (aLastModified) {
+        PrintTimeString(buf, sizeof(buf), aLastModified);
+        mBuffer.Append(buf);
+    } else {
+        mBuffer.AppendLiteral("No last modified time");
+    }
+    mBuffer.AppendLiteral("</td>\n");
+
+    // Expires time
+    mBuffer.AppendLiteral("    <td>");
+    if (aExpirationTime < 0xFFFFFFFF) {
+        PrintTimeString(buf, sizeof(buf), aExpirationTime);
+        mBuffer.Append(buf);
+    } else {
+        mBuffer.AppendLiteral("No expiration time");
+    }
+    mBuffer.AppendLiteral("</td>\n");
+
+    // Pinning
+    mBuffer.AppendLiteral("    <td>");
+    if (aPinned) {
+      mBuffer.Append(NS_LITERAL_CSTRING("Pinned"));
+    } else {
+      mBuffer.Append(NS_LITERAL_CSTRING("&nbsp;"));
+    }
+    mBuffer.AppendLiteral("</td>\n");
+
+    // Entry is done...
+    mBuffer.AppendLiteral("  </tr>\n");
+
+    return FlushBuffer();
+}
+
+NS_IMETHODIMP
+nsAboutCache::Channel::OnCacheEntryVisitCompleted()
+{
+    if (!mStream) {
+        return NS_ERROR_FAILURE;
+    }
+
+    if (mEntriesHeaderAdded) {
+        mBuffer.AppendLiteral("</table>\n");
+    }
+
+    // Kick another storage visiting (from a storage that allows us.)
+    while (mStorageList.Length()) {
+        nsresult rv = VisitNextStorage();
+        if (NS_SUCCEEDED(rv)) {
+            // Expecting new round of OnCache* calls.
+            return NS_OK;
+        }
+    }
+
+    // We are done!
+    mBuffer.AppendLiteral("</body>\n"
+                          "</html>\n");
+    nsresult rv = FlushBuffer();
+    if (NS_FAILED(rv)) {
+        NS_WARNING("Failed to flush buffer");
+    }
+    mStream->Close();
+
+    return NS_OK;
+}
+
+nsresult
+nsAboutCache::Channel::FlushBuffer()
+{
+    nsresult rv;
+
+    uint32_t bytesWritten;
+    rv = mStream->Write(mBuffer.get(), mBuffer.Length(), &bytesWritten);
+    mBuffer.Truncate();
+
+    if (NS_FAILED(rv)) {
+        mCancel = true;
+    }
+
+    return rv;
+}
+
+NS_IMETHODIMP
+nsAboutCache::GetURIFlags(nsIURI *aURI, uint32_t *result)
+{
+    *result = nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT;
+    return NS_OK;
+}
+
+// static
+nsresult
+nsAboutCache::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
+{
+    nsAboutCache* about = new nsAboutCache();
+    if (about == nullptr)
+        return NS_ERROR_OUT_OF_MEMORY;
+    NS_ADDREF(about);
+    nsresult rv = about->QueryInterface(aIID, aResult);
+    NS_RELEASE(about);
+    return rv;
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/netwerk/protocol/about/nsAboutCache.h b/netwerk/protocol/about/nsAboutCache.h
new file mode 100644
index 0000000000..c2d1af8505
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutCache.h
@@ -0,0 +1,136 @@
+/* -*- Mode: C++; tab-width: 2; 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 nsAboutCache_h__
+#define nsAboutCache_h__
+
+#include "nsIAboutModule.h"
+#include "nsICacheStorageVisitor.h"
+#include "nsICacheStorage.h"
+
+#include "nsString.h"
+#include "nsIOutputStream.h"
+#include "nsILoadContextInfo.h"
+
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+
+#define NS_FORWARD_SAFE_NSICHANNEL_SUBSET(_to) \
+  NS_IMETHOD GetOriginalURI(nsIURI * *aOriginalURI) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetOriginalURI(aOriginalURI); } \
+  NS_IMETHOD SetOriginalURI(nsIURI *aOriginalURI) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetOriginalURI(aOriginalURI); } \
+  NS_IMETHOD GetURI(nsIURI * *aURI) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetURI(aURI); } \
+  NS_IMETHOD GetOwner(nsISupports * *aOwner) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetOwner(aOwner); } \
+  NS_IMETHOD SetOwner(nsISupports *aOwner) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetOwner(aOwner); } \
+  NS_IMETHOD GetNotificationCallbacks(nsIInterfaceRequestor * *aNotificationCallbacks) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetNotificationCallbacks(aNotificationCallbacks); } \
+  NS_IMETHOD SetNotificationCallbacks(nsIInterfaceRequestor *aNotificationCallbacks) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetNotificationCallbacks(aNotificationCallbacks); } \
+  NS_IMETHOD GetSecurityInfo(nsISupports * *aSecurityInfo) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetSecurityInfo(aSecurityInfo); } \
+  NS_IMETHOD GetContentType(nsACString & aContentType) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetContentType(aContentType); } \
+  NS_IMETHOD SetContentType(const nsACString & aContentType) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetContentType(aContentType); } \
+  NS_IMETHOD GetContentCharset(nsACString & aContentCharset) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetContentCharset(aContentCharset); } \
+  NS_IMETHOD SetContentCharset(const nsACString & aContentCharset) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetContentCharset(aContentCharset); } \
+  NS_IMETHOD GetContentLength(int64_t *aContentLength) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetContentLength(aContentLength); } \
+  NS_IMETHOD SetContentLength(int64_t aContentLength) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetContentLength(aContentLength); } \
+  NS_IMETHOD GetContentDisposition(uint32_t *aContentDisposition) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetContentDisposition(aContentDisposition); } \
+  NS_IMETHOD SetContentDisposition(uint32_t aContentDisposition) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetContentDisposition(aContentDisposition); } \
+  NS_IMETHOD GetContentDispositionFilename(nsAString & aContentDispositionFilename) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetContentDispositionFilename(aContentDispositionFilename); } \
+  NS_IMETHOD SetContentDispositionFilename(const nsAString & aContentDispositionFilename) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetContentDispositionFilename(aContentDispositionFilename); } \
+  NS_IMETHOD GetContentDispositionHeader(nsACString & aContentDispositionHeader) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetContentDispositionHeader(aContentDispositionHeader); } \
+  NS_IMETHOD GetLoadInfo(nsILoadInfo * *aLoadInfo) override { return !_to ? NS_ERROR_NULL_POINTER : _to->GetLoadInfo(aLoadInfo); } \
+  NS_IMETHOD SetLoadInfo(nsILoadInfo *aLoadInfo) override { return !_to ? NS_ERROR_NULL_POINTER : _to->SetLoadInfo(aLoadInfo); } \
+
+class nsAboutCache final : public nsIAboutModule
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIABOUTMODULE
+
+    nsAboutCache() {}
+
+    static MOZ_MUST_USE nsresult
+    Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
+
+    static MOZ_MUST_USE nsresult
+    GetStorage(nsACString const & storageName, nsILoadContextInfo* loadInfo,
+               nsICacheStorage **storage);
+
+protected:
+    virtual ~nsAboutCache() {}
+
+    class Channel final : public nsIChannel
+                        , public nsICacheStorageVisitor
+    {
+        NS_DECL_ISUPPORTS
+        NS_DECL_NSICACHESTORAGEVISITOR
+        NS_FORWARD_SAFE_NSIREQUEST(mChannel)
+        NS_FORWARD_SAFE_NSICHANNEL_SUBSET(mChannel)
+        NS_IMETHOD AsyncOpen(nsIStreamListener *aListener, nsISupports *aContext) override;
+        NS_IMETHOD AsyncOpen2(nsIStreamListener *aListener) override;
+        NS_IMETHOD Open(nsIInputStream * *_retval) override;
+        NS_IMETHOD Open2(nsIInputStream * *_retval) override;
+
+    private:
+        virtual ~Channel() {}
+
+    public:
+        MOZ_MUST_USE nsresult Init(nsIURI* aURI, nsILoadInfo* aLoadInfo);
+        MOZ_MUST_USE nsresult ParseURI(nsIURI * uri, nsACString & storage);
+
+        // Finds a next storage we wish to visit (we use this method
+        // even there is a specified storage name, which is the only
+        // one in the list then.)  Posts FireVisitStorage() when found.
+        MOZ_MUST_USE nsresult VisitNextStorage();
+        // Helper method that calls VisitStorage() for the current storage.
+        // When it fails, OnCacheEntryVisitCompleted is simulated to close
+        // the output stream and thus the about:cache channel.
+        void FireVisitStorage();
+        // Kiks the visit cycle for the given storage, names can be:
+        // "disk", "memory", "appcache"
+        // Note: any newly added storage type has to be manually handled here.
+        MOZ_MUST_USE nsresult VisitStorage(nsACString const & storageName);
+
+        // Writes content of mBuffer to mStream and truncates
+        // the buffer.  It may fail when the input stream is closed by canceling
+        // the input stream channel.  It can be used to stop the cache iteration
+        // process.
+        MOZ_MUST_USE nsresult FlushBuffer();
+
+        // Whether we are showing overview status of all available
+        // storages.
+        bool mOverview;
+
+        // Flag initially false, that indicates the entries header has
+        // been added to the output HTML.
+        bool mEntriesHeaderAdded;
+
+        // Cancelation flag
+        bool mCancel;
+
+        // The context we are working with.
+        nsCOMPtr<nsILoadContextInfo> mLoadInfo;
+        nsCString mContextString;
+
+        // The list of all storage names we want to visit
+        nsTArray<nsCString> mStorageList;
+        nsCString mStorageName;
+        nsCOMPtr<nsICacheStorage> mStorage;
+
+        // Output data buffering and streaming output
+        nsCString mBuffer;
+        nsCOMPtr<nsIOutputStream> mStream;
+
+        // The input stream channel, the one that actually does the job
+        nsCOMPtr<nsIChannel> mChannel;
+    };
+};
+
+#define NS_ABOUT_CACHE_MODULE_CID                    \
+{ /* 9158c470-86e4-11d4-9be2-00e09872a416 */         \
+    0x9158c470,                                      \
+    0x86e4,                                          \
+    0x11d4,                                          \
+    {0x9b, 0xe2, 0x00, 0xe0, 0x98, 0x72, 0xa4, 0x16} \
+}
+
+#endif // nsAboutCache_h__
diff --git a/netwerk/protocol/about/nsAboutCacheEntry.cpp b/netwerk/protocol/about/nsAboutCacheEntry.cpp
new file mode 100644
index 0000000000..183395976e
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutCacheEntry.cpp
@@ -0,0 +1,603 @@
+/* -*- 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 "nsAboutCacheEntry.h"
+
+#include "mozilla/Sprintf.h"
+
+#include "nsAboutCache.h"
+#include "nsICacheStorage.h"
+#include "CacheObserver.h"
+#include "nsNetUtil.h"
+#include "nsEscape.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIAsyncOutputStream.h"
+#include "nsAboutProtocolUtils.h"
+#include "nsContentUtils.h"
+#include "nsInputStreamPump.h"
+#include "CacheFileUtils.h"
+#include <algorithm>
+#include "nsIPipe.h"
+
+using namespace mozilla::net;
+
+#define HEXDUMP_MAX_ROWS 16
+
+static void
+HexDump(uint32_t *state, const char *buf, int32_t n, nsCString &result)
+{
+  char temp[16];
+
+  const unsigned char *p;
+  while (n) {
+    SprintfLiteral(temp, "%08x:  ", *state);
+    result.Append(temp);
+    *state += HEXDUMP_MAX_ROWS;
+
+    p = (const unsigned char *) buf;
+
+    int32_t i, row_max = std::min(HEXDUMP_MAX_ROWS, n);
+
+    // print hex codes:
+    for (i = 0; i < row_max; ++i) {
+      SprintfLiteral(temp, "%02x  ", *p++);
+      result.Append(temp);
+    }
+    for (i = row_max; i < HEXDUMP_MAX_ROWS; ++i) {
+      result.AppendLiteral("    ");
+    }
+
+    // print ASCII glyphs if possible:
+    p = (const unsigned char *) buf;
+    for (i = 0; i < row_max; ++i, ++p) {
+      switch (*p) {
+      case '<':
+        result.AppendLiteral("&lt;");
+        break;
+      case '>':
+        result.AppendLiteral("&gt;");
+        break;
+      case '&':
+        result.AppendLiteral("&amp;");
+        break;
+      default:
+        if (*p < 0x7F && *p > 0x1F) {
+          result.Append(*p);
+        } else {
+          result.Append('.');
+        }
+      }
+    }
+
+    result.Append('\n');
+
+    buf += row_max;
+    n -= row_max;
+  }
+}
+
+//-----------------------------------------------------------------------------
+// nsAboutCacheEntry::nsISupports
+
+NS_IMPL_ISUPPORTS(nsAboutCacheEntry,
+                  nsIAboutModule)
+NS_IMPL_ISUPPORTS(nsAboutCacheEntry::Channel,
+                  nsICacheEntryOpenCallback,
+                  nsICacheEntryMetaDataVisitor,
+                  nsIStreamListener,
+                  nsIChannel)
+
+//-----------------------------------------------------------------------------
+// nsAboutCacheEntry::nsIAboutModule
+
+NS_IMETHODIMP
+nsAboutCacheEntry::NewChannel(nsIURI* uri,
+                              nsILoadInfo* aLoadInfo,
+                              nsIChannel** result)
+{
+    NS_ENSURE_ARG_POINTER(uri);
+    nsresult rv;
+
+    RefPtr<Channel> channel = new Channel();
+    rv = channel->Init(uri, aLoadInfo);
+    if (NS_FAILED(rv)) return rv;
+
+    channel.forget(result);
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutCacheEntry::GetURIFlags(nsIURI *aURI, uint32_t *result)
+{
+    *result = nsIAboutModule::HIDE_FROM_ABOUTABOUT |
+              nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT;
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsAboutCacheEntry::Channel
+
+nsresult
+nsAboutCacheEntry::Channel::Init(nsIURI* uri, nsILoadInfo* aLoadInfo)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIInputStream> stream;
+    rv = GetContentStream(uri, getter_AddRefs(stream));
+    if (NS_FAILED(rv)) return rv;
+
+    rv =  NS_NewInputStreamChannelInternal(getter_AddRefs(mChannel),
+                                           uri,
+                                           stream,
+                                           NS_LITERAL_CSTRING("text/html"),
+                                           NS_LITERAL_CSTRING("utf-8"),
+                                           aLoadInfo);
+    if (NS_FAILED(rv)) return rv;
+
+    return NS_OK;
+}
+
+nsresult
+nsAboutCacheEntry::Channel::GetContentStream(nsIURI *uri, nsIInputStream **result)
+{
+    nsresult rv;
+
+    // Init: (block size, maximum length)
+    nsCOMPtr<nsIAsyncInputStream> inputStream;
+    rv = NS_NewPipe2(getter_AddRefs(inputStream),
+                     getter_AddRefs(mOutputStream),
+                     true, false,
+                     256, UINT32_MAX);
+    if (NS_FAILED(rv)) return rv;
+
+    NS_NAMED_LITERAL_CSTRING(
+      buffer,
+      "<!DOCTYPE html>\n"
+      "<html>\n"
+      "<head>\n"
+      "  <title>Cache entry information</title>\n"
+      "  <link rel=\"stylesheet\" "
+      "href=\"chrome://global/skin/about.css\" type=\"text/css\"/>\n"
+      "  <link rel=\"stylesheet\" "
+      "href=\"chrome://global/skin/aboutCacheEntry.css\" type=\"text/css\"/>\n"
+      "</head>\n"
+      "<body>\n"
+      "<h1>Cache entry information</h1>\n");
+    uint32_t n;
+    rv = mOutputStream->Write(buffer.get(), buffer.Length(), &n);
+    if (NS_FAILED(rv)) return rv;
+    if (n != buffer.Length()) return NS_ERROR_UNEXPECTED;
+
+    rv = OpenCacheEntry(uri);
+    if (NS_FAILED(rv)) return rv;
+
+    inputStream.forget(result);
+    return NS_OK;
+}
+
+nsresult
+nsAboutCacheEntry::Channel::OpenCacheEntry(nsIURI *uri)
+{
+    nsresult rv;
+
+    rv = ParseURI(uri, mStorageName, getter_AddRefs(mLoadInfo),
+                       mEnhanceId, getter_AddRefs(mCacheURI));
+    if (NS_FAILED(rv)) return rv;
+
+    if (!CacheObserver::UseNewCache() &&
+        mLoadInfo->IsPrivate() &&
+        mStorageName.EqualsLiteral("disk")) {
+        // The cache v1 is storing all private entries in the memory-only
+        // cache, so it would not be found in the v1 disk cache.
+        mStorageName = NS_LITERAL_CSTRING("memory");
+    }
+
+    return OpenCacheEntry();
+}
+
+nsresult
+nsAboutCacheEntry::Channel::OpenCacheEntry()
+{
+    nsresult rv;
+
+    nsCOMPtr<nsICacheStorage> storage;
+    rv = nsAboutCache::GetStorage(mStorageName, mLoadInfo, getter_AddRefs(storage));
+    if (NS_FAILED(rv)) return rv;
+
+    // Invokes OnCacheEntryAvailable()
+    rv = storage->AsyncOpenURI(mCacheURI, mEnhanceId,
+                               nsICacheStorage::OPEN_READONLY |
+                               nsICacheStorage::OPEN_SECRETLY,
+                               this);
+    if (NS_FAILED(rv)) return rv;
+
+    return NS_OK;
+}
+
+nsresult
+nsAboutCacheEntry::Channel::ParseURI(nsIURI *uri,
+                                     nsACString &storageName,
+                                     nsILoadContextInfo **loadInfo,
+                                     nsCString &enahnceID,
+                                     nsIURI **cacheUri)
+{
+    //
+    // about:cache-entry?storage=[string]&contenxt=[string]&eid=[string]&uri=[string]
+    //
+    nsresult rv;
+
+    nsAutoCString path;
+    rv = uri->GetPath(path);
+    if (NS_FAILED(rv))
+        return rv;
+
+    nsACString::const_iterator keyBegin, keyEnd, valBegin, begin, end;
+    path.BeginReading(begin);
+    path.EndReading(end);
+
+    keyBegin = begin; keyEnd = end;
+    if (!FindInReadable(NS_LITERAL_CSTRING("?storage="), keyBegin, keyEnd))
+        return NS_ERROR_FAILURE;
+
+    valBegin = keyEnd; // the value of the storage key starts after the key
+
+    keyBegin = keyEnd; keyEnd = end;
+    if (!FindInReadable(NS_LITERAL_CSTRING("&context="), keyBegin, keyEnd))
+        return NS_ERROR_FAILURE;
+
+    storageName.Assign(Substring(valBegin, keyBegin));
+    valBegin = keyEnd; // the value of the context key starts after the key
+
+    keyBegin = keyEnd; keyEnd = end;
+    if (!FindInReadable(NS_LITERAL_CSTRING("&eid="), keyBegin, keyEnd))
+        return NS_ERROR_FAILURE;
+
+    nsAutoCString contextKey(Substring(valBegin, keyBegin));
+    valBegin = keyEnd; // the value of the eid key starts after the key
+
+    keyBegin = keyEnd; keyEnd = end;
+    if (!FindInReadable(NS_LITERAL_CSTRING("&uri="), keyBegin, keyEnd))
+        return NS_ERROR_FAILURE;
+
+    enahnceID.Assign(Substring(valBegin, keyBegin));
+
+    valBegin = keyEnd; // the value of the uri key starts after the key
+    nsAutoCString uriSpec(Substring(valBegin, end)); // uri is the last one
+
+    // Uf... parsing done, now get some objects from it...
+
+    nsCOMPtr<nsILoadContextInfo> info =
+      CacheFileUtils::ParseKey(contextKey);
+    if (!info)
+        return NS_ERROR_FAILURE;
+    info.forget(loadInfo);
+
+    rv = NS_NewURI(cacheUri, uriSpec);
+    if (NS_FAILED(rv))
+        return rv;
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsICacheEntryOpenCallback implementation
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsAboutCacheEntry::Channel::OnCacheEntryCheck(nsICacheEntry *aEntry,
+                                              nsIApplicationCache *aApplicationCache,
+                                              uint32_t *result)
+{
+    *result = nsICacheEntryOpenCallback::ENTRY_WANTED;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutCacheEntry::Channel::OnCacheEntryAvailable(nsICacheEntry *entry,
+                                                  bool isNew,
+                                                  nsIApplicationCache *aApplicationCache,
+                                                  nsresult status)
+{
+    nsresult rv;
+
+    mWaitingForData = false;
+    if (entry) {
+        rv = WriteCacheEntryDescription(entry);
+    } else if (!CacheObserver::UseNewCache() &&
+               !mLoadInfo->IsPrivate() &&
+               mStorageName.EqualsLiteral("memory")) {
+        // If we were not able to find the entry in the memory storage
+        // try again in the disk storage.
+        // This is a workaround for cache v1: when an originally disk
+        // cache entry is recreated as memory-only, it's clientID doesn't
+        // change and we cannot find it in "HTTP-memory-only" session.
+        // "Disk" cache storage looks at "HTTP".
+        mStorageName = NS_LITERAL_CSTRING("disk");
+        rv = OpenCacheEntry();
+        if (NS_SUCCEEDED(rv)) {
+            return NS_OK;
+        }
+    } else {
+        rv = WriteCacheEntryUnavailable();
+    }
+    if (NS_FAILED(rv)) return rv;
+
+
+    if (!mWaitingForData) {
+        // Data is not expected, close the output of content now.
+        CloseContent();
+    }
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// Print-out helper methods
+//-----------------------------------------------------------------------------
+
+#define APPEND_ROW(label, value) \
+    PR_BEGIN_MACRO \
+    buffer.AppendLiteral("  <tr>\n" \
+                         "    <th>"); \
+    buffer.AppendLiteral(label); \
+    buffer.AppendLiteral(":</th>\n" \
+                         "    <td>"); \
+    buffer.Append(value); \
+    buffer.AppendLiteral("</td>\n" \
+                         "  </tr>\n"); \
+    PR_END_MACRO
+
+nsresult
+nsAboutCacheEntry::Channel::WriteCacheEntryDescription(nsICacheEntry *entry)
+{
+    nsresult rv;
+    nsCString buffer;
+    uint32_t n;
+
+    nsAutoCString str;
+
+    rv = entry->GetKey(str);
+    if (NS_FAILED(rv)) return rv;
+
+    buffer.SetCapacity(4096);
+    buffer.AssignLiteral("<table>\n"
+                         "  <tr>\n"
+                         "    <th>key:</th>\n"
+                         "    <td id=\"td-key\">");
+
+    // Test if the key is actually a URI
+    nsCOMPtr<nsIURI> uri;
+    bool isJS = false;
+    bool isData = false;
+
+    rv = NS_NewURI(getter_AddRefs(uri), str);
+    // javascript: and data: URLs should not be linkified
+    // since clicking them can cause scripts to run - bug 162584
+    if (NS_SUCCEEDED(rv)) {
+        uri->SchemeIs("javascript", &isJS);
+        uri->SchemeIs("data", &isData);
+    }
+    char* escapedStr = nsEscapeHTML(str.get());
+    if (NS_SUCCEEDED(rv) && !(isJS || isData)) {
+        buffer.AppendLiteral("<a href=\"");
+        buffer.Append(escapedStr);
+        buffer.AppendLiteral("\">");
+        buffer.Append(escapedStr);
+        buffer.AppendLiteral("</a>");
+        uri = nullptr;
+    } else {
+        buffer.Append(escapedStr);
+    }
+    free(escapedStr);
+    buffer.AppendLiteral("</td>\n"
+                         "  </tr>\n");
+
+    // temp vars for reporting
+    char timeBuf[255];
+    uint32_t u = 0;
+    int32_t  i = 0;
+    nsAutoCString s;
+
+    // Fetch Count
+    s.Truncate();
+    entry->GetFetchCount(&i);
+    s.AppendInt(i);
+    APPEND_ROW("fetch count", s);
+
+    // Last Fetched
+    entry->GetLastFetched(&u);
+    if (u) {
+        PrintTimeString(timeBuf, sizeof(timeBuf), u);
+        APPEND_ROW("last fetched", timeBuf);
+    } else {
+        APPEND_ROW("last fetched", "No last fetch time (bug 1000338)");
+    }
+
+    // Last Modified
+    entry->GetLastModified(&u);
+    if (u) {
+        PrintTimeString(timeBuf, sizeof(timeBuf), u);
+        APPEND_ROW("last modified", timeBuf);
+    } else {
+        APPEND_ROW("last modified", "No last modified time (bug 1000338)");
+    }
+
+    // Expiration Time
+    entry->GetExpirationTime(&u);
+    if (u < 0xFFFFFFFF) {
+        PrintTimeString(timeBuf, sizeof(timeBuf), u);
+        APPEND_ROW("expires", timeBuf);
+    } else {
+        APPEND_ROW("expires", "No expiration time");
+    }
+
+    // Data Size
+    s.Truncate();
+    uint32_t dataSize;
+    if (NS_FAILED(entry->GetStorageDataSize(&dataSize)))
+        dataSize = 0;
+    s.AppendInt((int32_t)dataSize);     // XXX nsICacheEntryInfo interfaces should be fixed.
+    s.AppendLiteral(" B");
+    APPEND_ROW("Data size", s);
+
+    // TODO - mayhemer
+    // Here used to be a link to the disk file (in the old cache for entries that
+    // did not fit any of the block files, in the new cache every time).
+    // I'd rather have a small set of buttons here to action on the entry:
+    // 1. save the content
+    // 2. save as a complete HTTP response (response head, headers, content)
+    // 3. doom the entry
+    // A new bug(s) should be filed here.
+
+    // Security Info
+    nsCOMPtr<nsISupports> securityInfo;
+    entry->GetSecurityInfo(getter_AddRefs(securityInfo));
+    if (securityInfo) {
+        APPEND_ROW("Security", "This is a secure document.");
+    } else {
+        APPEND_ROW("Security",
+                   "This document does not have any security info associated with it.");
+    }
+
+    buffer.AppendLiteral("</table>\n"
+                         "<hr/>\n"
+                         "<table>\n");
+
+    mBuffer = &buffer;  // make it available for OnMetaDataElement().
+    entry->VisitMetaData(this);
+    mBuffer = nullptr;
+
+    buffer.AppendLiteral("</table>\n");
+    mOutputStream->Write(buffer.get(), buffer.Length(), &n);
+    buffer.Truncate();
+
+    // Provide a hexdump of the data
+    if (!dataSize) {
+        return NS_OK;
+    }
+
+    nsCOMPtr<nsIInputStream> stream;
+    entry->OpenInputStream(0, getter_AddRefs(stream));
+    if (!stream) {
+        return NS_OK;
+    }
+
+    RefPtr<nsInputStreamPump> pump;
+    rv = nsInputStreamPump::Create(getter_AddRefs(pump), stream);
+    if (NS_FAILED(rv)) {
+        return NS_OK; // just ignore
+    }
+
+    rv = pump->AsyncRead(this, nullptr);
+    if (NS_FAILED(rv)) {
+        return NS_OK; // just ignore
+    }
+
+    mWaitingForData = true;
+    return NS_OK;
+}
+
+nsresult
+nsAboutCacheEntry::Channel::WriteCacheEntryUnavailable()
+{
+    uint32_t n;
+    NS_NAMED_LITERAL_CSTRING(buffer,
+        "The cache entry you selected is not available.");
+    mOutputStream->Write(buffer.get(), buffer.Length(), &n);
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsICacheEntryMetaDataVisitor implementation
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsAboutCacheEntry::Channel::OnMetaDataElement(char const * key, char const * value)
+{
+    mBuffer->AppendLiteral("  <tr>\n"
+                           "    <th>");
+    mBuffer->Append(key);
+    mBuffer->AppendLiteral(":</th>\n"
+                           "    <td>");
+    char* escapedValue = nsEscapeHTML(value);
+    mBuffer->Append(escapedValue);
+    free(escapedValue);
+    mBuffer->AppendLiteral("</td>\n"
+                           "  </tr>\n");
+
+    return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsIStreamListener implementation
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsAboutCacheEntry::Channel::OnStartRequest(nsIRequest *request, nsISupports *ctx)
+{
+    mHexDumpState = 0;
+
+    NS_NAMED_LITERAL_CSTRING(buffer, "<hr/>\n<pre>");
+    uint32_t n;
+    return mOutputStream->Write(buffer.get(), buffer.Length(), &n);
+}
+
+NS_IMETHODIMP
+nsAboutCacheEntry::Channel::OnDataAvailable(nsIRequest *request, nsISupports *ctx,
+                                   nsIInputStream *aInputStream,
+                                   uint64_t aOffset,
+                                   uint32_t aCount)
+{
+    uint32_t n;
+    return aInputStream->ReadSegments(
+        &nsAboutCacheEntry::Channel::PrintCacheData, this, aCount, &n);
+}
+
+/* static */ nsresult
+nsAboutCacheEntry::Channel::PrintCacheData(nsIInputStream *aInStream,
+                                           void *aClosure,
+                                           const char *aFromSegment,
+                                           uint32_t aToOffset,
+                                           uint32_t aCount,
+                                           uint32_t *aWriteCount)
+{
+    nsAboutCacheEntry::Channel *a =
+      static_cast<nsAboutCacheEntry::Channel*>(aClosure);
+
+    nsCString buffer;
+    HexDump(&a->mHexDumpState, aFromSegment, aCount, buffer);
+
+    uint32_t n;
+    a->mOutputStream->Write(buffer.get(), buffer.Length(), &n);
+
+    *aWriteCount = aCount;
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutCacheEntry::Channel::OnStopRequest(nsIRequest *request, nsISupports *ctx,
+                                          nsresult result)
+{
+    NS_NAMED_LITERAL_CSTRING(buffer, "</pre>\n");
+    uint32_t n;
+    mOutputStream->Write(buffer.get(), buffer.Length(), &n);
+
+    CloseContent();
+
+    return NS_OK;
+}
+
+void
+nsAboutCacheEntry::Channel::CloseContent()
+{
+    NS_NAMED_LITERAL_CSTRING(buffer, "</body>\n</html>\n");
+    uint32_t n;
+    mOutputStream->Write(buffer.get(), buffer.Length(), &n);
+
+    mOutputStream->Close();
+    mOutputStream = nullptr;
+}
diff --git a/netwerk/protocol/about/nsAboutCacheEntry.h b/netwerk/protocol/about/nsAboutCacheEntry.h
new file mode 100644
index 0000000000..44a78760be
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutCacheEntry.h
@@ -0,0 +1,98 @@
+/* -*- 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 nsAboutCacheEntry_h__
+#define nsAboutCacheEntry_h__
+
+#include "nsIAboutModule.h"
+#include "nsICacheEntryOpenCallback.h"
+#include "nsICacheEntry.h"
+#include "nsIStreamListener.h"
+#include "nsString.h"
+#include "nsCOMPtr.h"
+
+class nsIAsyncOutputStream;
+class nsIInputStream;
+class nsILoadContextInfo;
+class nsIURI;
+class nsCString;
+
+class nsAboutCacheEntry final : public nsIAboutModule
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIABOUTMODULE
+
+private:
+    virtual ~nsAboutCacheEntry() {}
+
+    class Channel final : public nsICacheEntryOpenCallback
+                        , public nsICacheEntryMetaDataVisitor
+                        , public nsIStreamListener
+                        , public nsIChannel
+    {
+    public:
+        NS_DECL_ISUPPORTS
+        NS_DECL_NSICACHEENTRYOPENCALLBACK
+        NS_DECL_NSICACHEENTRYMETADATAVISITOR
+        NS_DECL_NSIREQUESTOBSERVER
+        NS_DECL_NSISTREAMLISTENER
+        NS_FORWARD_SAFE_NSICHANNEL(mChannel)
+        NS_FORWARD_SAFE_NSIREQUEST(mChannel)
+
+        Channel()
+            : mBuffer(nullptr)
+            , mWaitingForData(false)
+            , mHexDumpState(0)
+        {}
+
+    private:
+        virtual ~Channel() {}
+
+    public:
+        MOZ_MUST_USE nsresult Init(nsIURI* uri, nsILoadInfo* aLoadInfo);
+
+        MOZ_MUST_USE nsresult GetContentStream(nsIURI *, nsIInputStream **);
+        MOZ_MUST_USE nsresult OpenCacheEntry(nsIURI *);
+        MOZ_MUST_USE nsresult OpenCacheEntry();
+        MOZ_MUST_USE nsresult WriteCacheEntryDescription(nsICacheEntry *);
+        MOZ_MUST_USE nsresult WriteCacheEntryUnavailable();
+        MOZ_MUST_USE nsresult ParseURI(nsIURI *uri, nsACString &storageName,
+                                       nsILoadContextInfo **loadInfo,
+                                       nsCString &enahnceID,
+                                       nsIURI **cacheUri);
+        void CloseContent();
+
+        static MOZ_MUST_USE nsresult
+        PrintCacheData(nsIInputStream *aInStream,
+                       void *aClosure,
+                       const char *aFromSegment,
+                       uint32_t aToOffset,
+                       uint32_t aCount,
+                       uint32_t *aWriteCount);
+
+    private:
+        nsCString mStorageName, mEnhanceId;
+        nsCOMPtr<nsILoadContextInfo> mLoadInfo;
+        nsCOMPtr<nsIURI> mCacheURI;
+
+        nsCString *mBuffer;
+        nsCOMPtr<nsIAsyncOutputStream> mOutputStream;
+        bool mWaitingForData;
+        uint32_t mHexDumpState;
+
+        nsCOMPtr<nsIChannel> mChannel;
+    };
+};
+
+#define NS_ABOUT_CACHE_ENTRY_MODULE_CID              \
+{ /* 7fa5237d-b0eb-438f-9e50-ca0166e63788 */         \
+    0x7fa5237d,                                      \
+    0xb0eb,                                          \
+    0x438f,                                          \
+    {0x9e, 0x50, 0xca, 0x01, 0x66, 0xe6, 0x37, 0x88} \
+}
+
+#endif // nsAboutCacheEntry_h__
diff --git a/netwerk/protocol/about/nsAboutProtocolHandler.cpp b/netwerk/protocol/about/nsAboutProtocolHandler.cpp
new file mode 100644
index 0000000000..998fc71f95
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutProtocolHandler.cpp
@@ -0,0 +1,439 @@
+/* -*- Mode: C++; tab-width: 2; 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 "base/basictypes.h"
+#include "mozilla/ArrayUtils.h"
+
+#include "nsAboutProtocolHandler.h"
+#include "nsIURI.h"
+#include "nsIAboutModule.h"
+#include "nsString.h"
+#include "nsNetCID.h"
+#include "nsAboutProtocolUtils.h"
+#include "nsError.h"
+#include "nsNetUtil.h"
+#include "nsIObjectInputStream.h"
+#include "nsIObjectOutputStream.h"
+#include "nsAutoPtr.h"
+#include "nsIWritablePropertyBag2.h"
+#include "nsIChannel.h"
+#include "nsIScriptError.h"
+
+namespace mozilla {
+namespace net {
+
+static NS_DEFINE_CID(kSimpleURICID,     NS_SIMPLEURI_CID);
+static NS_DEFINE_CID(kNestedAboutURICID, NS_NESTEDABOUTURI_CID);
+
+static bool IsSafeForUntrustedContent(nsIAboutModule *aModule, nsIURI *aURI) {
+  uint32_t flags;
+  nsresult rv = aModule->GetURIFlags(aURI, &flags);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return (flags & nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT) != 0;
+}
+
+static bool IsSafeToLinkForUntrustedContent(nsIAboutModule *aModule, nsIURI *aURI) {
+  uint32_t flags;
+  nsresult rv = aModule->GetURIFlags(aURI, &flags);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return (flags & nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT) && (flags & nsIAboutModule::MAKE_LINKABLE);
+}
+////////////////////////////////////////////////////////////////////////////////
+
+NS_IMPL_ISUPPORTS(nsAboutProtocolHandler, nsIProtocolHandler,
+    nsIProtocolHandlerWithDynamicFlags, nsISupportsWeakReference)
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIProtocolHandler methods:
+
+NS_IMETHODIMP
+nsAboutProtocolHandler::GetScheme(nsACString &result)
+{
+    result.AssignLiteral("about");
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutProtocolHandler::GetDefaultPort(int32_t *result)
+{
+    *result = -1;        // no port for about: URLs
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutProtocolHandler::GetProtocolFlags(uint32_t *result)
+{
+    *result = URI_NORELATIVE | URI_NOAUTH | URI_DANGEROUS_TO_LOAD | URI_SCHEME_NOT_SELF_LINKABLE;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutProtocolHandler::GetFlagsForURI(nsIURI* aURI, uint32_t* aFlags)
+{
+    // First use the default (which is "unsafe for content"):
+    GetProtocolFlags(aFlags);
+
+    // Now try to see if this URI overrides the default:
+    nsCOMPtr<nsIAboutModule> aboutMod;
+    nsresult rv = NS_GetAboutModule(aURI, getter_AddRefs(aboutMod));
+    if (NS_FAILED(rv)) {
+      // Swallow this and just tell the consumer the default:
+      return NS_OK;
+    }
+    uint32_t aboutModuleFlags = 0;
+    rv = aboutMod->GetURIFlags(aURI, &aboutModuleFlags);
+    // This should never happen, so pass back the error:
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Secure (https) pages can load safe about pages without becoming
+    // mixed content.
+    if (aboutModuleFlags & nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT) {
+        *aFlags |= URI_SAFE_TO_LOAD_IN_SECURE_CONTEXT;
+        // about: pages can only be loaded by unprivileged principals
+        // if they are marked as LINKABLE
+        if (aboutModuleFlags & nsIAboutModule::MAKE_LINKABLE) {
+            // Replace URI_DANGEROUS_TO_LOAD with URI_LOADABLE_BY_ANYONE.
+            *aFlags &= ~URI_DANGEROUS_TO_LOAD;
+            *aFlags |= URI_LOADABLE_BY_ANYONE;
+        }
+    }
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutProtocolHandler::NewURI(const nsACString &aSpec,
+                               const char *aCharset, // ignore charset info
+                               nsIURI *aBaseURI,
+                               nsIURI **result)
+{
+    *result = nullptr;
+    nsresult rv;
+
+    // Use a simple URI to parse out some stuff first
+    nsCOMPtr<nsIURI> url = do_CreateInstance(kSimpleURICID, &rv);
+    if (NS_FAILED(rv)) return rv;
+
+    rv = url->SetSpec(aSpec);
+    if (NS_FAILED(rv)) {
+        return rv;
+    }
+
+    // Unfortunately, people create random about: URIs that don't correspond to
+    // about: modules...  Since those URIs will never open a channel, might as
+    // well consider them unsafe for better perf, and just in case.
+    bool isSafe = false;
+    
+    nsCOMPtr<nsIAboutModule> aboutMod;
+    rv = NS_GetAboutModule(url, getter_AddRefs(aboutMod));
+    if (NS_SUCCEEDED(rv)) {
+        isSafe = IsSafeToLinkForUntrustedContent(aboutMod, url);
+    }
+
+    if (isSafe) {
+        // We need to indicate that this baby is safe.  Use an inner URI that
+        // no one but the security manager will see.  Make sure to preserve our
+        // path, in case someone decides to hardcode checks for particular
+        // about: URIs somewhere.
+        nsAutoCString spec;
+        rv = url->GetPath(spec);
+        NS_ENSURE_SUCCESS(rv, rv);
+        
+        spec.Insert("moz-safe-about:", 0);
+
+        nsCOMPtr<nsIURI> inner;
+        rv = NS_NewURI(getter_AddRefs(inner), spec);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        nsSimpleNestedURI* outer = new nsNestedAboutURI(inner, aBaseURI);
+        NS_ENSURE_TRUE(outer, NS_ERROR_OUT_OF_MEMORY);
+
+        // Take a ref to it in the COMPtr we plan to return
+        url = outer;
+
+        rv = outer->SetSpec(aSpec);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // We don't want to allow mutation, since it would allow safe and
+    // unsafe URIs to change into each other...
+    NS_TryToSetImmutable(url);
+    url.swap(*result);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAboutProtocolHandler::NewChannel2(nsIURI* uri,
+                                    nsILoadInfo* aLoadInfo,
+                                    nsIChannel** result)
+{
+    NS_ENSURE_ARG_POINTER(uri);
+
+    // about:what you ask?
+    nsCOMPtr<nsIAboutModule> aboutMod;
+    nsresult rv = NS_GetAboutModule(uri, getter_AddRefs(aboutMod));
+
+    nsAutoCString path;
+    nsresult rv2 = NS_GetAboutModuleName(uri, path);
+    if (NS_SUCCEEDED(rv2) && path.EqualsLiteral("srcdoc")) {
+        // about:srcdoc is meant to be unresolvable, yet is included in the 
+        // about lookup tables so that it can pass security checks when used in
+        // a srcdoc iframe.  To ensure that it stays unresolvable, we pretend
+        // that it doesn't exist.
+      rv = NS_ERROR_FACTORY_NOT_REGISTERED;
+    }
+
+    if (NS_SUCCEEDED(rv)) {
+        // The standard return case:
+        rv = aboutMod->NewChannel(uri, aLoadInfo, result);
+        if (NS_SUCCEEDED(rv)) {
+            // Not all implementations of nsIAboutModule::NewChannel()
+            // set the LoadInfo on the newly created channel yet, as
+            // an interim solution we set the LoadInfo here if not
+            // available on the channel. Bug 1087720
+            nsCOMPtr<nsILoadInfo> loadInfo = (*result)->GetLoadInfo();
+            if (aLoadInfo != loadInfo) {
+                if (loadInfo) {
+                    NS_ASSERTION(false,
+                        "nsIAboutModule->newChannel(aURI, aLoadInfo) needs to set LoadInfo");
+                    const char16_t* params[] = {
+                        u"nsIAboutModule->newChannel(aURI)",
+                        u"nsIAboutModule->newChannel(aURI, aLoadInfo)"
+                    };
+                    nsContentUtils::ReportToConsole(
+                        nsIScriptError::warningFlag,
+                        NS_LITERAL_CSTRING("Security by Default"),
+                        nullptr, // aDocument
+                        nsContentUtils::eNECKO_PROPERTIES,
+                        "APIDeprecationWarning",
+                        params, mozilla::ArrayLength(params));
+                }
+                (*result)->SetLoadInfo(aLoadInfo);
+            }
+
+            // If this URI is safe for untrusted content, enforce that its
+            // principal be based on the channel's originalURI by setting the
+            // owner to null.
+            // Note: this relies on aboutMod's newChannel implementation
+            // having set the proper originalURI, which probably isn't ideal.
+            if (IsSafeForUntrustedContent(aboutMod, uri)) {
+                (*result)->SetOwner(nullptr);
+            }
+
+            RefPtr<nsNestedAboutURI> aboutURI;
+            nsresult rv2 = uri->QueryInterface(kNestedAboutURICID,
+                                               getter_AddRefs(aboutURI));
+            if (NS_SUCCEEDED(rv2) && aboutURI->GetBaseURI()) {
+                nsCOMPtr<nsIWritablePropertyBag2> writableBag =
+                    do_QueryInterface(*result);
+                if (writableBag) {
+                    writableBag->
+                        SetPropertyAsInterface(NS_LITERAL_STRING("baseURI"),
+                                               aboutURI->GetBaseURI());
+                }
+            }
+        }
+        return rv;
+    }
+
+    // mumble...
+
+    if (rv == NS_ERROR_FACTORY_NOT_REGISTERED) {
+        // This looks like an about: we don't know about.  Convert
+        // this to an invalid URI error.
+        rv = NS_ERROR_MALFORMED_URI;
+    }
+
+    return rv;
+}
+
+NS_IMETHODIMP
+nsAboutProtocolHandler::NewChannel(nsIURI* uri, nsIChannel* *result)
+{
+    return NewChannel2(uri, nullptr, result);
+}
+
+NS_IMETHODIMP 
+nsAboutProtocolHandler::AllowPort(int32_t port, const char *scheme, bool *_retval)
+{
+    // don't override anything.  
+    *_retval = false;
+    return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Safe about protocol handler impl
+
+NS_IMPL_ISUPPORTS(nsSafeAboutProtocolHandler, nsIProtocolHandler, nsISupportsWeakReference)
+
+// nsIProtocolHandler methods:
+
+NS_IMETHODIMP
+nsSafeAboutProtocolHandler::GetScheme(nsACString &result)
+{
+    result.AssignLiteral("moz-safe-about");
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSafeAboutProtocolHandler::GetDefaultPort(int32_t *result)
+{
+    *result = -1;        // no port for moz-safe-about: URLs
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSafeAboutProtocolHandler::GetProtocolFlags(uint32_t *result)
+{
+    *result = URI_NORELATIVE | URI_NOAUTH | URI_LOADABLE_BY_ANYONE | URI_SAFE_TO_LOAD_IN_SECURE_CONTEXT;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSafeAboutProtocolHandler::NewURI(const nsACString &aSpec,
+                                   const char *aCharset, // ignore charset info
+                                   nsIURI *aBaseURI,
+                                   nsIURI **result)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIURI> url = do_CreateInstance(kSimpleURICID, &rv);
+    if (NS_FAILED(rv)) return rv;
+
+    rv = url->SetSpec(aSpec);
+    if (NS_FAILED(rv)) {
+        return rv;
+    }
+
+    NS_TryToSetImmutable(url);
+    
+    *result = nullptr;
+    url.swap(*result);
+    return rv;
+}
+
+NS_IMETHODIMP
+nsSafeAboutProtocolHandler::NewChannel2(nsIURI* uri,
+                                        nsILoadInfo* aLoadInfo,
+                                        nsIChannel** result)
+{
+    *result = nullptr;
+    return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsSafeAboutProtocolHandler::NewChannel(nsIURI* uri, nsIChannel* *result)
+{
+    *result = nullptr;
+    return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP 
+nsSafeAboutProtocolHandler::AllowPort(int32_t port, const char *scheme, bool *_retval)
+{
+    // don't override anything.  
+    *_retval = false;
+    return NS_OK;
+}
+
+////////////////////////////////////////////////////////////
+// nsNestedAboutURI implementation
+NS_INTERFACE_MAP_BEGIN(nsNestedAboutURI)
+  if (aIID.Equals(kNestedAboutURICID))
+      foundInterface = static_cast<nsIURI*>(this);
+  else
+NS_INTERFACE_MAP_END_INHERITING(nsSimpleNestedURI)
+
+// nsISerializable
+NS_IMETHODIMP
+nsNestedAboutURI::Read(nsIObjectInputStream* aStream)
+{
+    nsresult rv = nsSimpleNestedURI::Read(aStream);
+    if (NS_FAILED(rv)) return rv;
+
+    bool haveBase;
+    rv = aStream->ReadBoolean(&haveBase);
+    if (NS_FAILED(rv)) return rv;
+
+    if (haveBase) {
+        nsCOMPtr<nsISupports> supports;
+        rv = aStream->ReadObject(true, getter_AddRefs(supports));
+        if (NS_FAILED(rv)) return rv;
+
+        mBaseURI = do_QueryInterface(supports, &rv);
+        if (NS_FAILED(rv)) return rv;
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsNestedAboutURI::Write(nsIObjectOutputStream* aStream)
+{
+    nsresult rv = nsSimpleNestedURI::Write(aStream);
+    if (NS_FAILED(rv)) return rv;
+
+    rv = aStream->WriteBoolean(mBaseURI != nullptr);
+    if (NS_FAILED(rv)) return rv;
+
+    if (mBaseURI) {
+        // A previous iteration of this code wrote out mBaseURI as nsISupports
+        // and then read it in as nsIURI, which is non-kosher when mBaseURI
+        // implements more than just a single line of interfaces and the
+        // canonical nsISupports* isn't the one a static_cast<> of mBaseURI
+        // would produce.  For backwards compatibility with existing
+        // serializations we continue to write mBaseURI as nsISupports but
+        // switch to reading it as nsISupports, with a post-read QI to get to
+        // nsIURI.
+        rv = aStream->WriteCompoundObject(mBaseURI, NS_GET_IID(nsISupports),
+                                          true);
+        if (NS_FAILED(rv)) return rv;
+    }
+
+    return NS_OK;
+}
+
+// nsSimpleURI
+/* virtual */ nsSimpleURI*
+nsNestedAboutURI::StartClone(nsSimpleURI::RefHandlingEnum aRefHandlingMode,
+                             const nsACString& aNewRef)
+{
+    // Sadly, we can't make use of nsSimpleNestedURI::StartClone here.
+    // However, this function is expected to exactly match that function,
+    // aside from the "new ns***URI()" call.
+    NS_ENSURE_TRUE(mInnerURI, nullptr);
+
+    nsCOMPtr<nsIURI> innerClone;
+    nsresult rv;
+    if (aRefHandlingMode == eHonorRef) {
+        rv = mInnerURI->Clone(getter_AddRefs(innerClone));
+    } else if (aRefHandlingMode == eReplaceRef) {
+        rv = mInnerURI->CloneWithNewRef(aNewRef, getter_AddRefs(innerClone));
+    } else {
+        rv = mInnerURI->CloneIgnoringRef(getter_AddRefs(innerClone));
+    }
+
+    if (NS_FAILED(rv)) {
+        return nullptr;
+    }
+
+    nsNestedAboutURI* url = new nsNestedAboutURI(innerClone, mBaseURI);
+    SetRefOnClone(url, aRefHandlingMode, aNewRef);
+    url->SetMutable(false);
+
+    return url;
+}
+
+// nsIClassInfo
+NS_IMETHODIMP
+nsNestedAboutURI::GetClassIDNoAlloc(nsCID *aClassIDNoAlloc)
+{
+    *aClassIDNoAlloc = kNestedAboutURICID;
+    return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/protocol/about/nsAboutProtocolHandler.h b/netwerk/protocol/about/nsAboutProtocolHandler.h
new file mode 100644
index 0000000000..72c7e8e668
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutProtocolHandler.h
@@ -0,0 +1,90 @@
+/* -*- Mode: C++; tab-width: 2; 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 nsAboutProtocolHandler_h___
+#define nsAboutProtocolHandler_h___
+
+#include "nsIProtocolHandler.h"
+#include "nsSimpleNestedURI.h"
+#include "nsWeakReference.h"
+#include "mozilla/Attributes.h"
+
+class nsIURI;
+
+namespace mozilla {
+namespace net {
+
+class nsAboutProtocolHandler : public nsIProtocolHandlerWithDynamicFlags
+                             , public nsIProtocolHandler
+                             , public nsSupportsWeakReference
+{
+public:
+    NS_DECL_ISUPPORTS
+
+    // nsIProtocolHandler methods:
+    NS_DECL_NSIPROTOCOLHANDLER
+    NS_DECL_NSIPROTOCOLHANDLERWITHDYNAMICFLAGS
+
+    // nsAboutProtocolHandler methods:
+    nsAboutProtocolHandler() {}
+
+private:
+    virtual ~nsAboutProtocolHandler() {}
+};
+
+class nsSafeAboutProtocolHandler final : public nsIProtocolHandler
+                                       , public nsSupportsWeakReference
+{
+public:
+    NS_DECL_ISUPPORTS
+
+    // nsIProtocolHandler methods:
+    NS_DECL_NSIPROTOCOLHANDLER
+
+    // nsSafeAboutProtocolHandler methods:
+    nsSafeAboutProtocolHandler() {}
+
+private:
+    ~nsSafeAboutProtocolHandler() {}
+};
+
+
+// Class to allow us to propagate the base URI to about:blank correctly
+class nsNestedAboutURI : public nsSimpleNestedURI {
+public:
+    nsNestedAboutURI(nsIURI* aInnerURI, nsIURI* aBaseURI)
+        : nsSimpleNestedURI(aInnerURI)
+        , mBaseURI(aBaseURI)
+    {}
+
+    // For use only from deserialization
+    nsNestedAboutURI() : nsSimpleNestedURI() {}
+
+    virtual ~nsNestedAboutURI() {}
+
+    // Override QI so we can QI to our CID as needed
+    NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr);
+
+    // Override StartClone(), the nsISerializable methods, and
+    // GetClassIDNoAlloc; this last is needed to make our nsISerializable impl
+    // work right.
+    virtual nsSimpleURI* StartClone(RefHandlingEnum aRefHandlingMode,
+                                    const nsACString& newRef);
+    NS_IMETHOD Read(nsIObjectInputStream* aStream);
+    NS_IMETHOD Write(nsIObjectOutputStream* aStream);
+    NS_IMETHOD GetClassIDNoAlloc(nsCID *aClassIDNoAlloc);
+
+    nsIURI* GetBaseURI() const {
+        return mBaseURI;
+    }
+
+protected:
+    nsCOMPtr<nsIURI> mBaseURI;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif /* nsAboutProtocolHandler_h___ */
diff --git a/netwerk/protocol/about/nsAboutProtocolUtils.h b/netwerk/protocol/about/nsAboutProtocolUtils.h
new file mode 100644
index 0000000000..c5946412b0
--- /dev/null
+++ b/netwerk/protocol/about/nsAboutProtocolUtils.h
@@ -0,0 +1,71 @@
+/* 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 nsAboutProtocolUtils_h
+#define nsAboutProtocolUtils_h
+
+#include "nsIURI.h"
+#include "nsString.h"
+#include "nsReadableUtils.h"
+#include "nsIAboutModule.h"
+#include "nsServiceManagerUtils.h"
+#include "prtime.h"
+
+inline MOZ_MUST_USE nsresult
+NS_GetAboutModuleName(nsIURI *aAboutURI, nsCString& aModule)
+{
+#ifdef DEBUG
+    {
+        bool isAbout;
+        NS_ASSERTION(NS_SUCCEEDED(aAboutURI->SchemeIs("about", &isAbout)) &&
+                     isAbout,
+                     "should be used only on about: URIs");
+    }
+#endif
+
+    nsresult rv = aAboutURI->GetPath(aModule);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    int32_t f = aModule.FindCharInSet(NS_LITERAL_CSTRING("#?"));
+    if (f != kNotFound) {
+        aModule.Truncate(f);
+    }
+
+    // convert to lowercase, as all about: modules are lowercase
+    ToLowerCase(aModule);
+    return NS_OK;
+}
+
+inline nsresult
+NS_GetAboutModule(nsIURI *aAboutURI, nsIAboutModule** aModule)
+{
+  NS_PRECONDITION(aAboutURI, "Must have URI");
+
+  nsAutoCString contractID;
+  nsresult rv = NS_GetAboutModuleName(aAboutURI, contractID);
+  if (NS_FAILED(rv)) return rv;
+
+  // look up a handler to deal with "what"
+  contractID.Insert(NS_LITERAL_CSTRING(NS_ABOUT_MODULE_CONTRACTID_PREFIX), 0);
+
+  return CallGetService(contractID.get(), aModule);
+}
+
+inline PRTime SecondsToPRTime(uint32_t t_sec)
+{
+    PRTime t_usec, usec_per_sec;
+    t_usec = t_sec;
+    usec_per_sec = PR_USEC_PER_SEC;
+    return t_usec *= usec_per_sec;
+}
+inline void PrintTimeString(char *buf, uint32_t bufsize, uint32_t t_sec)
+{
+    PRExplodedTime et;
+    PRTime t_usec = SecondsToPRTime(t_sec);
+    PR_ExplodeTime(t_usec, PR_LocalTimeParameters, &et);
+    PR_FormatTime(buf, bufsize, "%Y-%m-%d %H:%M:%S", &et);
+}
+
+
+#endif
diff --git a/netwerk/protocol/about/nsIAboutModule.idl b/netwerk/protocol/about/nsIAboutModule.idl
new file mode 100644
index 0000000000..230cd6c056
--- /dev/null
+++ b/netwerk/protocol/about/nsIAboutModule.idl
@@ -0,0 +1,88 @@
+/* -*- Mode: C++; tab-width: 2; 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 nsIURI;
+interface nsIChannel;
+interface nsILoadInfo;
+
+[scriptable, uuid(c0c19db9-1b5a-4ac5-b656-ed6f8149fa48)]
+interface nsIAboutModule : nsISupports 
+{
+
+    /**
+     * Constructs a new channel for the about protocol module. 
+     *
+     * @param aURI the uri of the new channel
+     * @param aLoadInfo the loadinfo of the new channel
+     */
+    nsIChannel newChannel(in nsIURI aURI,
+                          in nsILoadInfo aLoadInfo);
+
+    /**
+     * A flag that indicates whether a URI should be run with content
+     * privileges. If it is, the about: protocol handler will enforce that
+     * the principal of channels created for it be based on their
+     * originalURI or URI (depending on the channel flags), by setting
+     * their "owner" to null.
+     * If content needs to be able to link to this URI, specify
+     * URI_CONTENT_LINKABLE as well.
+     */
+    const unsigned long URI_SAFE_FOR_UNTRUSTED_CONTENT = (1 << 0);
+
+    /**
+     * A flag that indicates whether script should be enabled for the
+     * given about: URI even if it's disabled in general.
+     */
+    const unsigned long ALLOW_SCRIPT = (1 << 1);
+
+    /**
+     * A flag that indicates whether this about: URI doesn't want to be listed
+     * in about:about, especially if it's not useful without a query string.
+     */
+    const unsigned long HIDE_FROM_ABOUTABOUT = (1 << 2);
+
+    /**
+     * A flag that indicates whether this about: URI wants Indexed DB enabled.
+     */
+    const unsigned long ENABLE_INDEXED_DB = (1 << 3);
+
+    /**
+     * A flag that indicates that this URI can be loaded in a child process
+     */
+    const unsigned long URI_CAN_LOAD_IN_CHILD = (1 << 4);
+
+    /**
+     * A flag that indicates that this URI must be loaded in a child process
+     */
+    const unsigned long URI_MUST_LOAD_IN_CHILD = (1 << 5);
+
+    /**
+     * Obsolete. This flag no longer has any effect and will be removed in future.
+     */
+    const unsigned long MAKE_UNLINKABLE = (1 << 6);
+
+    /**
+     * A flag that indicates that this URI should be linkable from content.
+     * Ignored unless URI_SAFE_FOR_UNTRUSTED_CONTENT is also specified.
+     */
+    const unsigned long MAKE_LINKABLE = (1 << 7);
+
+    /**
+     * A method to get the flags that apply to a given about: URI.  The URI
+     * passed in is guaranteed to be one of the URIs that this module
+     * registered to deal with.
+     */
+    unsigned long getURIFlags(in nsIURI aURI);
+};
+
+%{C++
+
+#define NS_ABOUT_MODULE_CONTRACTID        "@mozilla.org/network/protocol/about;1" 
+#define NS_ABOUT_MODULE_CONTRACTID_PREFIX NS_ABOUT_MODULE_CONTRACTID "?what=" 
+#define NS_ABOUT_MODULE_CONTRACTID_LENGTH 49      // strlen(NS_ABOUT_MODULE_CONTRACTID_PREFIX)
+
+%}