--- a/browser/components/about/AboutRedirector.cpp
+++ b/browser/components/about/AboutRedirector.cpp
@@ -8,23 +8,26 @@
 #include "AboutRedirector.h"
 #include "nsNetUtil.h"
 #include "nsIAboutNewTabService.h"
 #include "nsIChannel.h"
 #include "nsIURI.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsIProtocolHandler.h"
 #include "mozilla/ArrayUtils.h"
+#include "mozilla/Preferences.h"
 #include "nsServiceManagerUtils.h"
 
 namespace mozilla {
 namespace browser {
 
 NS_IMPL_ISUPPORTS(AboutRedirector, nsIAboutModule)
 
+bool AboutRedirector::sUseOldPreferences = false;
+
 struct RedirEntry {
   const char* id;
   const char* url;
   uint32_t flags;
 };
 
 /*
   Entries which do not have URI_SAFE_FOR_UNTRUSTED_CONTENT will run with chrome
@@ -133,27 +136,36 @@ AboutRedirector::NewChannel(nsIURI* aURI
   NS_ASSERTION(result, "must not be null");
 
   nsAutoCString path = GetAboutModuleName(aURI);
 
   nsresult rv;
   nsCOMPtr<nsIIOService> ioService = do_GetIOService(&rv);
   NS_ENSURE_SUCCESS(rv, rv);
 
+  static bool sPrefCacheInited = false;
+  if (!sPrefCacheInited) {
+    Preferences::AddBoolVarCache(&sUseOldPreferences,
+                                 "browser.preferences.useOldOrganization");
+    sPrefCacheInited = true;
+  }
+
   for (auto & redir : kRedirMap) {
     if (!strcmp(path.get(), redir.id)) {
       nsAutoCString url;
 
       if (path.EqualsLiteral("newtab")) {
         // let the aboutNewTabService decide where to redirect
         nsCOMPtr<nsIAboutNewTabService> aboutNewTabService =
           do_GetService("@mozilla.org/browser/aboutnewtab-service;1", &rv);
         NS_ENSURE_SUCCESS(rv, rv);
         rv = aboutNewTabService->GetDefaultURL(url);
         NS_ENSURE_SUCCESS(rv, rv);
+      } else if (path.EqualsLiteral("preferences") && sUseOldPreferences) {
+        url.AssignASCII("chrome://browser/content/preferences/in-content-old/preferences.xul");
       }
       // fall back to the specified url in the map
       if (url.IsEmpty()) {
         url.AssignASCII(redir.url);
       }
 
       nsCOMPtr<nsIChannel> tempChannel;
       nsCOMPtr<nsIURI> tempURI;

--- a/browser/components/about/AboutRedirector.h
+++ b/browser/components/about/AboutRedirector.h
@@ -19,14 +19,17 @@ public:
  
   AboutRedirector() {}
 
   static nsresult
     Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
 
 protected:
   virtual ~AboutRedirector() {}
+
+private:
+  static bool sUseOldPreferences;
 };
 
 } // namespace browser
 } // namespace mozilla
 
 #endif // AboutRedirector_h__

copy from browser/components/preferences/in-content/advanced.js
copy to browser/components/preferences/in-content-old/advanced.js

copy from browser/components/preferences/in-content/advanced.xul
copy to browser/components/preferences/in-content-old/advanced.xul
--- a/browser/components/preferences/in-content/advanced.xul
+++ b/browser/components/preferences/in-content-old/advanced.xul
@@ -1,16 +1,16 @@
 # 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/.
 
 <!-- Advanced panel -->
 
 <script type="application/javascript"
-        src="chrome://browser/content/preferences/in-content/advanced.js"/>
+        src="chrome://browser/content/preferences/in-content-old/advanced.js"/>
 
 <preferences id="advancedPreferences" hidden="true" data-category="paneAdvanced">
   <preference id="browser.preferences.advanced.selectedTabIndex"
               name="browser.preferences.advanced.selectedTabIndex"
               type="int"/>
 
   <!-- General tab -->
   <preference id="accessibility.browsewithcaret"
@@ -115,17 +115,17 @@
               name="security.OCSP.enabled"
               type="int"/>
 </preferences>
 
 #ifdef HAVE_SHELL_SERVICE
   <stringbundle id="bundleShell" src="chrome://browser/locale/shellservice.properties"/>
   <stringbundle id="bundleBrand" src="chrome://branding/locale/brand.properties"/>
 #endif
-  <stringbundle id="bundlePreferences" src="chrome://browser/locale/preferences/preferences.properties"/>
+  <stringbundle id="bundlePreferences" src="chrome://browser/locale/preferences-old/preferences.properties"/>
 
 <hbox id="header-advanced"
       class="header"
       hidden="true"
       data-category="paneAdvanced">
   <label class="header-name" flex="1">&paneAdvanced.title;</label>
   <html:a class="help-button" target="_blank" aria-label="&helpButton.label;"></html:a>
 </hbox>

copy from browser/components/preferences/in-content/applications.js
copy to browser/components/preferences/in-content-old/applications.js

copy from browser/components/preferences/in-content/applications.xul
copy to browser/components/preferences/in-content-old/applications.xul
--- a/browser/components/preferences/in-content/applications.xul
+++ b/browser/components/preferences/in-content-old/applications.xul
@@ -1,16 +1,16 @@
 # 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/.
 
 <!-- Applications panel -->
 
 <script type="application/javascript"
-        src="chrome://browser/content/preferences/in-content/applications.js"/>
+        src="chrome://browser/content/preferences/in-content-old/applications.js"/>
 
 <preferences id="feedsPreferences" hidden="true" data-category="paneApplications">
   <preference id="browser.feeds.handler"
               name="browser.feeds.handler"
               type="string"/>
   <preference id="browser.feeds.handler.default"
               name="browser.feeds.handler.default"
               type="string"/>

copy from browser/components/preferences/in-content/containers.js
copy to browser/components/preferences/in-content-old/containers.js
--- a/browser/components/preferences/in-content/containers.js
+++ b/browser/components/preferences/in-content-old/containers.js
@@ -2,17 +2,17 @@
  * 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/. */
 
 /* import-globals-from preferences.js */
 
 Components.utils.import("resource://gre/modules/AppConstants.jsm");
 Components.utils.import("resource://gre/modules/ContextualIdentityService.jsm");
 
-const containersBundle = Services.strings.createBundle("chrome://browser/locale/preferences/containers.properties");
+const containersBundle = Services.strings.createBundle("chrome://browser/locale/preferences-old/containers.properties");
 
 const defaultContainerIcon = "fingerprint";
 const defaultContainerColor = "blue";
 
 let gContainersPane = {
 
   init() {
     this._list = document.getElementById("containersView");

copy from browser/components/preferences/in-content/containers.xul
copy to browser/components/preferences/in-content-old/containers.xul
--- a/browser/components/preferences/in-content/containers.xul
+++ b/browser/components/preferences/in-content-old/containers.xul
@@ -1,16 +1,16 @@
 # 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/.
 
 <!-- Containers panel -->
 
 <script type="application/javascript"
-        src="chrome://browser/content/preferences/in-content/containers.js"/>
+        src="chrome://browser/content/preferences/in-content-old/containers.js"/>
 
 <preferences id="containerPreferences" hidden="true" data-category="paneContainer">
   <!-- Containers -->
   <preference id="privacy.userContext.enabled"
               name="privacy.userContext.enabled"
               type="bool"/>
 
 </preferences>

copy from browser/components/preferences/in-content/content.js
copy to browser/components/preferences/in-content-old/content.js

copy from browser/components/preferences/in-content/content.xul
copy to browser/components/preferences/in-content-old/content.xul
--- a/browser/components/preferences/in-content/content.xul
+++ b/browser/components/preferences/in-content-old/content.xul
@@ -25,17 +25,17 @@
   <preference id="browser.translation.detectLanguage"
               name="browser.translation.detectLanguage"
               type="bool"/>
 </preferences>
 
 <script type="application/javascript"
         src="chrome://mozapps/content/preferences/fontbuilder.js"/>
 <script type="application/javascript"
-        src="chrome://browser/content/preferences/in-content/content.js"/>
+        src="chrome://browser/content/preferences/in-content-old/content.js"/>
 
 <hbox id="header-content"
       class="header"
       hidden="true"
       data-category="paneContent">
   <label class="header-name" flex="1">&paneContent.title;</label>
   <html:a class="help-button" target="_blank" aria-label="&helpButton.label;"></html:a>
 </hbox>

copy from browser/components/preferences/in-content/jar.mn
copy to browser/components/preferences/in-content-old/jar.mn
--- a/browser/components/preferences/in-content/jar.mn
+++ b/browser/components/preferences/in-content-old/jar.mn
@@ -1,18 +1,18 @@
 # 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/.
 
 browser.jar:
-   content/browser/preferences/in-content/preferences.js
-*  content/browser/preferences/in-content/preferences.xul
-   content/browser/preferences/in-content/subdialogs.js
+   content/browser/preferences/in-content-old/preferences.js
+*  content/browser/preferences/in-content-old/preferences.xul
+   content/browser/preferences/in-content-old/subdialogs.js
 
-   content/browser/preferences/in-content/main.js
-   content/browser/preferences/in-content/privacy.js
-   content/browser/preferences/in-content/containers.js
-   content/browser/preferences/in-content/advanced.js
-   content/browser/preferences/in-content/applications.js
-   content/browser/preferences/in-content/content.js
-   content/browser/preferences/in-content/sync.js
-   content/browser/preferences/in-content/security.js
-   content/browser/preferences/in-content/search.js
+   content/browser/preferences/in-content-old/main.js
+   content/browser/preferences/in-content-old/privacy.js
+   content/browser/preferences/in-content-old/containers.js
+   content/browser/preferences/in-content-old/advanced.js
+   content/browser/preferences/in-content-old/applications.js
+   content/browser/preferences/in-content-old/content.js
+   content/browser/preferences/in-content-old/sync.js
+   content/browser/preferences/in-content-old/security.js
+   content/browser/preferences/in-content-old/search.js

copy from browser/components/preferences/in-content/main.js
copy to browser/components/preferences/in-content-old/main.js

copy from browser/components/preferences/in-content/main.xul
copy to browser/components/preferences/in-content-old/main.xul
--- a/browser/components/preferences/in-content/main.xul
+++ b/browser/components/preferences/in-content-old/main.xul
@@ -1,16 +1,16 @@
 # 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/.
 
 <!-- General panel -->
 
 <script type="application/javascript"
-        src="chrome://browser/content/preferences/in-content/main.js"/>
+        src="chrome://browser/content/preferences/in-content-old/main.js"/>
 
 <preferences id="mainPreferences" hidden="true" data-category="paneGeneral">
 
 #ifdef E10S_TESTING_ONLY
     <preference id="browser.tabs.remote.autostart"
                 name="browser.tabs.remote.autostart"
                 type="bool"/>
     <preference id="e10sTempPref"

copy from browser/components/preferences/in-content/moz.build
copy to browser/components/preferences/in-content-old/moz.build

copy from browser/components/preferences/in-content/preferences.js
copy to browser/components/preferences/in-content-old/preferences.js

copy from browser/components/preferences/in-content/preferences.xul
copy to browser/components/preferences/in-content-old/preferences.xul
--- a/browser/components/preferences/in-content/preferences.xul
+++ b/browser/components/preferences/in-content-old/preferences.xul
@@ -7,41 +7,41 @@
 
 <?xml-stylesheet href="chrome://browser/skin/preferences/preferences.css"?>
 <?xml-stylesheet href="chrome://global/skin/in-content/common.css"?>
 <?xml-stylesheet
   href="chrome://browser/skin/preferences/in-content/preferences.css"?>
 <?xml-stylesheet
   href="chrome://browser/content/preferences/handlers.css"?>
 <?xml-stylesheet href="chrome://browser/skin/preferences/applications.css"?>
-<?xml-stylesheet href="chrome://browser/skin/preferences/in-content/search.css"?>
-<?xml-stylesheet href="chrome://browser/skin/preferences/in-content/containers.css"?>
+<?xml-stylesheet href="chrome://browser/skin/preferences/in-content-old/search.css"?>
+<?xml-stylesheet href="chrome://browser/skin/preferences/in-content-old/containers.css"?>
 
 <!DOCTYPE page [
 <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd">
 <!ENTITY % globalPreferencesDTD SYSTEM "chrome://global/locale/preferences.dtd">
 <!ENTITY % preferencesDTD SYSTEM
-  "chrome://browser/locale/preferences/preferences.dtd">
-<!ENTITY % privacyDTD SYSTEM "chrome://browser/locale/preferences/privacy.dtd">
-<!ENTITY % tabsDTD SYSTEM "chrome://browser/locale/preferences/tabs.dtd">
-<!ENTITY % searchDTD SYSTEM "chrome://browser/locale/preferences/search.dtd">
+  "chrome://browser/locale/preferences-old/preferences.dtd">
+<!ENTITY % privacyDTD SYSTEM "chrome://browser/locale/preferences-old/privacy.dtd">
+<!ENTITY % tabsDTD SYSTEM "chrome://browser/locale/preferences-old/tabs.dtd">
+<!ENTITY % searchDTD SYSTEM "chrome://browser/locale/preferences-old/search.dtd">
 <!ENTITY % syncBrandDTD SYSTEM "chrome://browser/locale/syncBrand.dtd">
-<!ENTITY % syncDTD SYSTEM "chrome://browser/locale/preferences/sync.dtd">
+<!ENTITY % syncDTD SYSTEM "chrome://browser/locale/preferences-old/sync.dtd">
 <!ENTITY % securityDTD SYSTEM
-  "chrome://browser/locale/preferences/security.dtd">
+  "chrome://browser/locale/preferences-old/security.dtd">
 <!ENTITY % containersDTD SYSTEM
-  "chrome://browser/locale/preferences/containers.dtd">
+  "chrome://browser/locale/preferences-old/containers.dtd">
 <!ENTITY % sanitizeDTD SYSTEM "chrome://browser/locale/sanitize.dtd">
-<!ENTITY % mainDTD SYSTEM "chrome://browser/locale/preferences/main.dtd">
+<!ENTITY % mainDTD SYSTEM "chrome://browser/locale/preferences-old/main.dtd">
 <!ENTITY % aboutHomeDTD SYSTEM "chrome://browser/locale/aboutHome.dtd">
-<!ENTITY % contentDTD SYSTEM "chrome://browser/locale/preferences/content.dtd">
+<!ENTITY % contentDTD SYSTEM "chrome://browser/locale/preferences-old/content.dtd">
 <!ENTITY % applicationsDTD SYSTEM
-  "chrome://browser/locale/preferences/applications.dtd">
+  "chrome://browser/locale/preferences-old/applications.dtd">
 <!ENTITY % advancedDTD SYSTEM
-  "chrome://browser/locale/preferences/advanced.dtd">
+  "chrome://browser/locale/preferences-old/advanced.dtd">
 %brandDTD;
 %globalPreferencesDTD;
 %preferencesDTD;
 %privacyDTD;
 %tabsDTD;
 %searchDTD;
 %syncBrandDTD;
 %syncDTD;
@@ -64,32 +64,32 @@
       disablefastfind="true"
 #ifdef USE_WIN_TITLE_STYLE
       title="&prefWindow.titleWin;">
 #else
       title="&prefWindow.title;">
 #endif
 
   <html:link rel="shortcut icon"
-              href="chrome://browser/skin/preferences/in-content/favicon.ico"/>
+              href="chrome://browser/skin/preferences/in-content-old/favicon.ico"/>
 
   <script type="application/javascript"
           src="chrome://browser/content/utilityOverlay.js"/>
   <script type="application/javascript"
-          src="chrome://browser/content/preferences/in-content/preferences.js"/>
-  <script src="chrome://browser/content/preferences/in-content/subdialogs.js"/>
+          src="chrome://browser/content/preferences/in-content-old/preferences.js"/>
+  <script src="chrome://browser/content/preferences/in-content-old/subdialogs.js"/>
 
   <stringbundle id="bundleBrand"
                 src="chrome://branding/locale/brand.properties"/>
   <stringbundle id="bundlePreferences"
-                src="chrome://browser/locale/preferences/preferences.properties"/>
+                src="chrome://browser/locale/preferences-old/preferences.properties"/>
 
   <stringbundleset id="appManagerBundleset">
     <stringbundle id="appManagerBundle"
-                  src="chrome://browser/locale/preferences/applicationManager.properties"/>
+                  src="chrome://browser/locale/preferences-old/applicationManager.properties"/>
   </stringbundleset>
 
   <stack flex="1">
   <hbox flex="1">
 
     <!-- category list -->
     <richlistbox id="categories">
       <richlistitem id="category-general"

copy from browser/components/preferences/in-content/privacy.js
copy to browser/components/preferences/in-content-old/privacy.js

copy from browser/components/preferences/in-content/privacy.xul
copy to browser/components/preferences/in-content-old/privacy.xul
--- a/browser/components/preferences/in-content/privacy.xul
+++ b/browser/components/preferences/in-content-old/privacy.xul
@@ -1,16 +1,16 @@
 # 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/.
 
 <!-- Privacy panel -->
 
 <script type="application/javascript"
-        src="chrome://browser/content/preferences/in-content/privacy.js"/>
+        src="chrome://browser/content/preferences/in-content-old/privacy.js"/>
 
 <preferences id="privacyPreferences" hidden="true" data-category="panePrivacy">
 
   <!-- Tracking -->
   <preference id="privacy.trackingprotection.enabled"
               name="privacy.trackingprotection.enabled"
               type="bool"/>
   <preference id="privacy.trackingprotection.pbmode.enabled"

copy from browser/components/preferences/in-content/search.js
copy to browser/components/preferences/in-content-old/search.js

copy from browser/components/preferences/in-content/search.xul
copy to browser/components/preferences/in-content-old/search.xul
--- a/browser/components/preferences/in-content/search.xul
+++ b/browser/components/preferences/in-content-old/search.xul
@@ -10,17 +10,17 @@
 
       <preference id="browser.search.hiddenOneOffs"
                   name="browser.search.hiddenOneOffs"
                   type="unichar"/>
 
     </preferences>
 
     <script type="application/javascript"
-            src="chrome://browser/content/preferences/in-content/search.js"/>
+            src="chrome://browser/content/preferences/in-content-old/search.js"/>
 
     <stringbundle id="engineManagerBundle" src="chrome://browser/locale/engineManager.properties"/>
 
     <hbox id="header-search"
           class="header"
           hidden="true"
           data-category="paneSearch">
       <label class="header-name" flex="1">&paneSearch.title;</label>

copy from browser/components/preferences/in-content/security.js
copy to browser/components/preferences/in-content-old/security.js

copy from browser/components/preferences/in-content/security.xul
copy to browser/components/preferences/in-content-old/security.xul
--- a/browser/components/preferences/in-content/security.xul
+++ b/browser/components/preferences/in-content-old/security.xul
@@ -1,16 +1,16 @@
 # 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/.
 
 <!-- Security panel -->
 
 <script type="application/javascript"
-        src="chrome://browser/content/preferences/in-content/security.js"/>
+        src="chrome://browser/content/preferences/in-content-old/security.js"/>
 
 <preferences id="securityPreferences" hidden="true" data-category="paneSecurity">
   <!-- XXX buttons -->
   <preference id="pref.privacy.disable_button.view_passwords"
               name="pref.privacy.disable_button.view_passwords"
               type="bool"/>
   <preference id="pref.privacy.disable_button.view_passwords_exceptions"
               name="pref.privacy.disable_button.view_passwords_exceptions"

copy from browser/components/preferences/in-content/subdialogs.js
copy to browser/components/preferences/in-content-old/subdialogs.js
--- a/browser/components/preferences/in-content/subdialogs.js
+++ b/browser/components/preferences/in-content-old/subdialogs.js
@@ -12,19 +12,19 @@ var gSubDialog = {
   _closingEvent: null,
   _isClosing: false,
   _frame: null,
   _overlay: null,
   _box: null,
   _openedURL: null,
   _injectedStyleSheets: [
     "chrome://browser/skin/preferences/preferences.css",
-    "chrome://global/skin/in-content/common.css",
-    "chrome://browser/skin/preferences/in-content/preferences.css",
-    "chrome://browser/skin/preferences/in-content/dialog.css",
+    "chrome://global/skin/in-content-old/common.css",
+    "chrome://browser/skin/preferences/in-content-old/preferences.css",
+    "chrome://browser/skin/preferences/in-content-old/dialog.css",
   ],
   _resizeObserver: null,
 
   init() {
     this._frame = document.getElementById("dialogFrame");
     this._overlay = document.getElementById("dialogOverlay");
     this._box = document.getElementById("dialogBox");
     this._closeButton = document.getElementById("dialogClose");

copy from browser/components/preferences/in-content/sync.js
copy to browser/components/preferences/in-content-old/sync.js

copy from browser/components/preferences/in-content/sync.xul
copy to browser/components/preferences/in-content-old/sync.xul
--- a/browser/components/preferences/in-content/sync.xul
+++ b/browser/components/preferences/in-content-old/sync.xul
@@ -21,17 +21,17 @@
               name="services.sync.engine.prefs"
               type="bool"/>
   <preference id="engine.passwords"
               name="services.sync.engine.passwords"
               type="bool"/>
 </preferences>
 
 <script type="application/javascript"
-        src="chrome://browser/content/preferences/in-content/sync.js"/>
+        src="chrome://browser/content/preferences/in-content-old/sync.js"/>
 
 <hbox id="header-sync"
       class="header"
       hidden="true"
       data-category="paneSync">
   <label class="header-name" flex="1">&paneSync.title;</label>
   <html:a class="help-button text-link" target="_blank" aria-label="&helpButton.label;"></html:a>
 </hbox>

copy from browser/components/preferences/in-content/tests/.eslintrc.js
copy to browser/components/preferences/in-content-old/tests/.eslintrc.js

copy from browser/components/preferences/in-content/tests/browser.ini
copy to browser/components/preferences/in-content-old/tests/browser.ini

copy from browser/components/preferences/in-content/tests/browser_advanced_siteData.js
copy to browser/components/preferences/in-content-old/tests/browser_advanced_siteData.js
--- a/browser/components/preferences/in-content/tests/browser_advanced_siteData.js
+++ b/browser/components/preferences/in-content-old/tests/browser_advanced_siteData.js
@@ -6,17 +6,17 @@
 const { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 /* import-globals-from ../../../../../testing/modules/sinon-1.16.1.js */
 Services.scriptloader.loadSubScript("resource://testing-common/sinon-1.16.1.js");
 
 const TEST_HOST = "example.com";
 const TEST_ORIGIN = "http://" + TEST_HOST;
-const TEST_BASE_URL = TEST_ORIGIN + "/browser/browser/components/preferences/in-content/tests/";
+const TEST_BASE_URL = TEST_ORIGIN + "/browser/browser/components/preferences/in-content-old/tests/";
 const REMOVE_DIALOG_URL = "chrome://browser/content/preferences/siteDataRemoveSelected.xul";
 
 const { NetUtil } = Cu.import("resource://gre/modules/NetUtil.jsm", {});
 const { SiteDataManager } = Cu.import("resource:///modules/SiteDataManager.jsm", {});
 const { OfflineAppCacheHelper } = Cu.import("resource:///modules/offlineAppCache.jsm", {});
 
 const mockOfflineAppCacheHelper = {
   clear: null,

copy from browser/components/preferences/in-content/tests/browser_advanced_update.js
copy to browser/components/preferences/in-content-old/tests/browser_advanced_update.js

copy from browser/components/preferences/in-content/tests/browser_applications_selection.js
copy to browser/components/preferences/in-content-old/tests/browser_applications_selection.js

copy from browser/components/preferences/in-content/tests/browser_basic_rebuild_fonts_test.js
copy to browser/components/preferences/in-content-old/tests/browser_basic_rebuild_fonts_test.js

copy from browser/components/preferences/in-content/tests/browser_bug1018066_resetScrollPosition.js
copy to browser/components/preferences/in-content-old/tests/browser_bug1018066_resetScrollPosition.js

copy from browser/components/preferences/in-content/tests/browser_bug1020245_openPreferences_to_paneContent.js
copy to browser/components/preferences/in-content-old/tests/browser_bug1020245_openPreferences_to_paneContent.js

copy from browser/components/preferences/in-content/tests/browser_bug1184989_prevent_scrolling_when_preferences_flipped.js
copy to browser/components/preferences/in-content-old/tests/browser_bug1184989_prevent_scrolling_when_preferences_flipped.js

copy from browser/components/preferences/in-content/tests/browser_bug1184989_prevent_scrolling_when_preferences_flipped.xul
copy to browser/components/preferences/in-content-old/tests/browser_bug1184989_prevent_scrolling_when_preferences_flipped.xul

copy from browser/components/preferences/in-content/tests/browser_bug410900.js
copy to browser/components/preferences/in-content-old/tests/browser_bug410900.js

copy from browser/components/preferences/in-content/tests/browser_bug705422.js
copy to browser/components/preferences/in-content-old/tests/browser_bug705422.js

copy from browser/components/preferences/in-content/tests/browser_bug731866.js
copy to browser/components/preferences/in-content-old/tests/browser_bug731866.js

copy from browser/components/preferences/in-content/tests/browser_bug795764_cachedisabled.js
copy to browser/components/preferences/in-content-old/tests/browser_bug795764_cachedisabled.js

copy from browser/components/preferences/in-content/tests/browser_change_app_handler.js
copy to browser/components/preferences/in-content-old/tests/browser_change_app_handler.js

copy from browser/components/preferences/in-content/tests/browser_connection.js
copy to browser/components/preferences/in-content-old/tests/browser_connection.js

copy from browser/components/preferences/in-content/tests/browser_connection_bug388287.js
copy to browser/components/preferences/in-content-old/tests/browser_connection_bug388287.js

copy from browser/components/preferences/in-content/tests/browser_cookies_exceptions.js
copy to browser/components/preferences/in-content-old/tests/browser_cookies_exceptions.js

copy from browser/components/preferences/in-content/tests/browser_defaultbrowser_alwayscheck.js
copy to browser/components/preferences/in-content-old/tests/browser_defaultbrowser_alwayscheck.js

copy from browser/components/preferences/in-content/tests/browser_healthreport.js
copy to browser/components/preferences/in-content-old/tests/browser_healthreport.js

copy from browser/components/preferences/in-content/tests/browser_homepages_filter_aboutpreferences.js
copy to browser/components/preferences/in-content-old/tests/browser_homepages_filter_aboutpreferences.js

copy from browser/components/preferences/in-content/tests/browser_notifications_do_not_disturb.js
copy to browser/components/preferences/in-content-old/tests/browser_notifications_do_not_disturb.js

copy from browser/components/preferences/in-content/tests/browser_permissions_urlFieldHidden.js
copy to browser/components/preferences/in-content-old/tests/browser_permissions_urlFieldHidden.js

copy from browser/components/preferences/in-content/tests/browser_privacypane_1.js
copy to browser/components/preferences/in-content-old/tests/browser_privacypane_1.js

copy from browser/components/preferences/in-content/tests/browser_privacypane_3.js
copy to browser/components/preferences/in-content-old/tests/browser_privacypane_3.js

copy from browser/components/preferences/in-content/tests/browser_privacypane_4.js
copy to browser/components/preferences/in-content-old/tests/browser_privacypane_4.js

copy from browser/components/preferences/in-content/tests/browser_privacypane_5.js
copy to browser/components/preferences/in-content-old/tests/browser_privacypane_5.js

copy from browser/components/preferences/in-content/tests/browser_privacypane_8.js
copy to browser/components/preferences/in-content-old/tests/browser_privacypane_8.js

copy from browser/components/preferences/in-content/tests/browser_proxy_backup.js
copy to browser/components/preferences/in-content-old/tests/browser_proxy_backup.js

copy from browser/components/preferences/in-content/tests/browser_sanitizeOnShutdown_prefLocked.js
copy to browser/components/preferences/in-content-old/tests/browser_sanitizeOnShutdown_prefLocked.js

copy from browser/components/preferences/in-content/tests/browser_searchsuggestions.js
copy to browser/components/preferences/in-content-old/tests/browser_searchsuggestions.js

copy from browser/components/preferences/in-content/tests/browser_security.js
copy to browser/components/preferences/in-content-old/tests/browser_security.js

copy from browser/components/preferences/in-content/tests/browser_subdialogs.js
copy to browser/components/preferences/in-content-old/tests/browser_subdialogs.js

copy from browser/components/preferences/in-content/tests/browser_telemetry.js
copy to browser/components/preferences/in-content-old/tests/browser_telemetry.js

copy from browser/components/preferences/in-content/tests/head.js
copy to browser/components/preferences/in-content-old/tests/head.js
--- a/browser/components/preferences/in-content/tests/head.js
+++ b/browser/components/preferences/in-content-old/tests/head.js
@@ -1,13 +1,22 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 Components.utils.import("resource://gre/modules/Promise.jsm");
 
+// Tests within /browser/components/preferences/in-content-old/tests/
+// test the "old" preferences organization, before it was reorganized.
+// Thus, all of these tests should revert back to the "oldOrganization"
+// before running.
+Services.prefs.setBoolPref("browser.preferences.useOldOrganization", true);
+registerCleanupFunction(function() {
+  Services.prefs.clearUserPref("browser.preferences.useOldOrganization");
+});
+
 const kDefaultWait = 2000;
 
 function is_hidden(aElement) {
   var style = aElement.ownerGlobal.getComputedStyle(aElement);
   if (style.display == "none")
     return true;
   if (style.visibility != "visible")
     return true;

copy from browser/components/preferences/in-content/tests/privacypane_tests_perwindow.js
copy to browser/components/preferences/in-content-old/tests/privacypane_tests_perwindow.js

copy from browser/components/preferences/in-content/tests/site_data_test.html
copy to browser/components/preferences/in-content-old/tests/site_data_test.html

copy from browser/components/preferences/in-content/tests/subdialog.xul
copy to browser/components/preferences/in-content-old/tests/subdialog.xul

copy from browser/components/preferences/in-content/tests/subdialog2.xul
copy to browser/components/preferences/in-content-old/tests/subdialog2.xul

--- a/browser/components/preferences/moz.build
+++ b/browser/components/preferences/moz.build
@@ -1,18 +1,22 @@
 # -*- 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/.
 
-DIRS += ['in-content']
+DIRS += [
+	'in-content-old',
+	'in-content'
+]
 
 BROWSER_CHROME_MANIFESTS += [
-    'in-content/tests/browser.ini',
+    'in-content-old/tests/browser.ini',
+    'in-content/tests/browser.ini'
 ]
 
 for var in ('MOZ_APP_NAME', 'MOZ_MACBUNDLE_NAME'):
     DEFINES[var] = CONFIG[var]
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('windows', 'gtk2', 'gtk3', 'cocoa'):
     DEFINES['HAVE_SHELL_SERVICE'] = 1
 

--- a/browser/installer/allowed-dupes.mn
+++ b/browser/installer/allowed-dupes.mn
@@ -5,16 +5,63 @@
 # PLEASE DO NOT ADD MORE EXCEPTIONS TO THIS LIST
 #
 
 # updater on osx is bug 1311194
 LaunchServices/org.mozilla.updater
 updater.app/Contents/MacOS/org.mozilla.updater
 updater.app/Contents/PkgInfo
 browser/chrome.manifest
+# browser preferences fork is bug 1349689
+browser/chrome/browser/content/browser/preferences/in-content-old/advanced.js
+browser/chrome/browser/content/browser/preferences/in-content-old/applications.js
+browser/chrome/browser/content/browser/preferences/in-content-old/containers.js
+browser/chrome/browser/content/browser/preferences/in-content-old/content.js
+browser/chrome/browser/content/browser/preferences/in-content-old/main.js
+browser/chrome/browser/content/browser/preferences/in-content-old/preferences.js
+browser/chrome/browser/content/browser/preferences/in-content-old/privacy.js
+browser/chrome/browser/content/browser/preferences/in-content-old/search.js
+browser/chrome/browser/content/browser/preferences/in-content-old/security.js
+browser/chrome/browser/content/browser/preferences/in-content-old/sync.js
+browser/chrome/browser/content/browser/preferences/in-content/advanced.js
+browser/chrome/browser/content/browser/preferences/in-content/applications.js
+browser/chrome/browser/content/browser/preferences/in-content/containers.js
+browser/chrome/browser/content/browser/preferences/in-content/content.js
+browser/chrome/browser/content/browser/preferences/in-content/main.js
+browser/chrome/browser/content/browser/preferences/in-content/preferences.js
+browser/chrome/browser/content/browser/preferences/in-content/privacy.js
+browser/chrome/browser/content/browser/preferences/in-content/search.js
+browser/chrome/browser/content/browser/preferences/in-content/security.js
+browser/chrome/browser/content/browser/preferences/in-content/sync.js
+browser/chrome/en-US/locale/browser/preferences-old/applications.dtd
+browser/chrome/en-US/locale/browser/preferences-old/containers.properties
+browser/chrome/en-US/locale/browser/preferences-old/containers.dtd
+browser/chrome/en-US/locale/browser/preferences-old/tabs.dtd
+browser/chrome/en-US/locale/browser/preferences-old/preferences.dtd
+browser/chrome/en-US/locale/browser/preferences-old/search.dtd
+browser/chrome/en-US/locale/browser/preferences-old/security.dtd
+browser/chrome/en-US/locale/browser/preferences-old/main.dtd
+browser/chrome/en-US/locale/browser/preferences-old/content.dtd
+browser/chrome/en-US/locale/browser/preferences-old/sync.dtd
+browser/chrome/en-US/locale/browser/preferences-old/privacy.dtd
+browser/chrome/en-US/locale/browser/preferences-old/advanced.dtd
+browser/chrome/en-US/locale/browser/preferences-old/preferences.properties
+browser/chrome/en-US/locale/browser/preferences/applications.dtd
+browser/chrome/en-US/locale/browser/preferences/containers.properties
+browser/chrome/en-US/locale/browser/preferences/containers.dtd
+browser/chrome/en-US/locale/browser/preferences/tabs.dtd
+browser/chrome/en-US/locale/browser/preferences/preferences.dtd
+browser/chrome/en-US/locale/browser/preferences/search.dtd
+browser/chrome/en-US/locale/browser/preferences/security.dtd
+browser/chrome/en-US/locale/browser/preferences/main.dtd
+browser/chrome/en-US/locale/browser/preferences/content.dtd
+browser/chrome/en-US/locale/browser/preferences/sync.dtd
+browser/chrome/en-US/locale/browser/preferences/privacy.dtd
+browser/chrome/en-US/locale/browser/preferences/advanced.dtd
+browser/chrome/en-US/locale/browser/preferences/preferences.properties
 # browser branding / themes is bug 1313106
 browser/chrome/browser/content/branding/icon128.png
 browser/chrome/browser/content/branding/icon16.png
 browser/chrome/browser/content/branding/icon32.png
 browser/chrome/browser/content/branding/icon48.png
 browser/chrome/browser/content/browser/defaultthemes/5.footer.png
 browser/chrome/browser/content/browser/defaultthemes/5.header.png
 browser/chrome/browser/content/browser/extension.svg

copy from browser/locales/en-US/chrome/browser/preferences/advanced.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/advanced.dtd

copy from browser/locales/en-US/chrome/browser/preferences/applications.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/applications.dtd

copy from browser/locales/en-US/chrome/browser/preferences/containers.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/containers.dtd

copy from browser/locales/en-US/chrome/browser/preferences/containers.properties
copy to browser/locales/en-US/chrome/browser/preferences-old/containers.properties

copy from browser/locales/en-US/chrome/browser/preferences/content.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/content.dtd

copy from browser/locales/en-US/chrome/browser/preferences/main.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/main.dtd

copy from browser/locales/en-US/chrome/browser/preferences/preferences.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/preferences.dtd

copy from browser/locales/en-US/chrome/browser/preferences/preferences.properties
copy to browser/locales/en-US/chrome/browser/preferences-old/preferences.properties

copy from browser/locales/en-US/chrome/browser/preferences/privacy.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/privacy.dtd

copy from browser/locales/en-US/chrome/browser/preferences/search.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/search.dtd

copy from browser/locales/en-US/chrome/browser/preferences/security.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/security.dtd

copy from browser/locales/en-US/chrome/browser/preferences/sync.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/sync.dtd

copy from browser/locales/en-US/chrome/browser/preferences/tabs.dtd
copy to browser/locales/en-US/chrome/browser/preferences-old/tabs.dtd

--- a/browser/locales/jar.mn
+++ b/browser/locales/jar.mn
@@ -45,49 +45,62 @@
     locale/browser/translation.properties          (%chrome/browser/translation.properties)
     locale/browser/webrtcIndicator.properties      (%chrome/browser/webrtcIndicator.properties)
     locale/browser/downloads/downloads.dtd         (%chrome/browser/downloads/downloads.dtd)
     locale/browser/downloads/downloads.properties  (%chrome/browser/downloads/downloads.properties)
     locale/browser/places/places.dtd               (%chrome/browser/places/places.dtd)
     locale/browser/places/places.properties        (%chrome/browser/places/places.properties)
     locale/browser/places/editBookmarkOverlay.dtd  (%chrome/browser/places/editBookmarkOverlay.dtd)
     locale/browser/places/bookmarkProperties.properties (%chrome/browser/places/bookmarkProperties.properties)
-    locale/browser/preferences/selectBookmark.dtd  (%chrome/browser/preferences/selectBookmark.dtd)
     locale/browser/places/moveBookmarks.dtd        (%chrome/browser/places/moveBookmarks.dtd)
     locale/browser/safebrowsing/phishing-afterload-warning-message.dtd (%chrome/browser/safebrowsing/phishing-afterload-warning-message.dtd)
     locale/browser/safebrowsing/report-phishing.dtd                    (%chrome/browser/safebrowsing/report-phishing.dtd)
     locale/browser/safebrowsing/safebrowsing.properties   (%chrome/browser/safebrowsing/safebrowsing.properties)
     locale/browser/feeds/subscribe.dtd              (%chrome/browser/feeds/subscribe.dtd)
     locale/browser/feeds/subscribe.properties       (%chrome/browser/feeds/subscribe.properties)
     locale/browser/migration/migration.dtd         (%chrome/browser/migration/migration.dtd)
     locale/browser/migration/migration.properties  (%chrome/browser/migration/migration.properties)
+    locale/browser/preferences-old/advanced.dtd       (%chrome/browser/preferences-old/advanced.dtd)
     locale/browser/preferences/advanced.dtd           (%chrome/browser/preferences/advanced.dtd)
-    locale/browser/preferences/applicationManager.dtd        (%chrome/browser/preferences/applicationManager.dtd)
-    locale/browser/preferences/applicationManager.properties (%chrome/browser/preferences/applicationManager.properties)
+    locale/browser/preferences/applicationManager.dtd     (%chrome/browser/preferences/applicationManager.dtd)
+    locale/browser/preferences/applicationManager.properties     (%chrome/browser/preferences/applicationManager.properties)
+    locale/browser/preferences-old/applications.dtd   (%chrome/browser/preferences-old/applications.dtd)
+    locale/browser/preferences/applications.dtd       (%chrome/browser/preferences/applications.dtd)
     locale/browser/preferences/blocklists.dtd         (%chrome/browser/preferences/blocklists.dtd)
     locale/browser/preferences/colors.dtd             (%chrome/browser/preferences/colors.dtd)
-    locale/browser/preferences/cookies.dtd            (%chrome/browser/preferences/cookies.dtd)
+    locale/browser/preferences/connection.dtd         (%chrome/browser/preferences/connection.dtd)
+    locale/browser/preferences-old/containers.dtd     (%chrome/browser/preferences-old/containers.dtd)
+    locale/browser/preferences/containers.dtd         (%chrome/browser/preferences/containers.dtd)
+    locale/browser/preferences-old/containers.properties (%chrome/browser/preferences-old/containers.properties)
+    locale/browser/preferences/containers.properties     (%chrome/browser/preferences/containers.properties)
+    locale/browser/preferences-old/content.dtd        (%chrome/browser/preferences-old/content.dtd)
     locale/browser/preferences/content.dtd            (%chrome/browser/preferences/content.dtd)
-    locale/browser/preferences/connection.dtd         (%chrome/browser/preferences/connection.dtd)
+    locale/browser/preferences/cookies.dtd            (%chrome/browser/preferences/cookies.dtd)
     locale/browser/preferences/donottrack.dtd         (%chrome/browser/preferences/donottrack.dtd)
-    locale/browser/preferences/applications.dtd       (%chrome/browser/preferences/applications.dtd)
     locale/browser/preferences/fonts.dtd              (%chrome/browser/preferences/fonts.dtd)
+    locale/browser/preferences/languages.dtd          (%chrome/browser/preferences/languages.dtd)
+    locale/browser/preferences-old/main.dtd           (%chrome/browser/preferences-old/main.dtd)
     locale/browser/preferences/main.dtd               (%chrome/browser/preferences/main.dtd)
-    locale/browser/preferences/languages.dtd          (%chrome/browser/preferences/languages.dtd)
     locale/browser/preferences/permissions.dtd        (%chrome/browser/preferences/permissions.dtd)
+    locale/browser/preferences-old/preferences.dtd    (%chrome/browser/preferences-old/preferences.dtd)
     locale/browser/preferences/preferences.dtd        (%chrome/browser/preferences/preferences.dtd)
-    locale/browser/preferences/preferences.properties (%chrome/browser/preferences/preferences.properties)
-    locale/browser/preferences/containers.properties  (%chrome/browser/preferences/containers.properties)
+    locale/browser/preferences-old/preferences.properties (%chrome/browser/preferences-old/preferences.properties)
+    locale/browser/preferences/preferences.properties     (%chrome/browser/preferences/preferences.properties)
+    locale/browser/preferences-old/privacy.dtd        (%chrome/browser/preferences-old/privacy.dtd)
     locale/browser/preferences/privacy.dtd            (%chrome/browser/preferences/privacy.dtd)
+    locale/browser/preferences-old/search.dtd         (%chrome/browser/preferences-old/search.dtd)
+    locale/browser/preferences/search.dtd             (%chrome/browser/preferences/search.dtd)
+    locale/browser/preferences-old/security.dtd       (%chrome/browser/preferences-old/security.dtd)
     locale/browser/preferences/security.dtd           (%chrome/browser/preferences/security.dtd)
-    locale/browser/preferences/containers.dtd         (%chrome/browser/preferences/containers.dtd)
+    locale/browser/preferences/selectBookmark.dtd     (%chrome/browser/preferences/selectBookmark.dtd)
+    locale/browser/preferences/siteDataSettings.dtd     (%chrome/browser/preferences/siteDataSettings.dtd)
+    locale/browser/preferences-old/sync.dtd           (%chrome/browser/preferences-old/sync.dtd)
     locale/browser/preferences/sync.dtd               (%chrome/browser/preferences/sync.dtd)
+    locale/browser/preferences-old/tabs.dtd           (%chrome/browser/preferences-old/tabs.dtd)
     locale/browser/preferences/tabs.dtd               (%chrome/browser/preferences/tabs.dtd)
-    locale/browser/preferences/search.dtd             (%chrome/browser/preferences/search.dtd)
-    locale/browser/preferences/siteDataSettings.dtd   (%chrome/browser/preferences/siteDataSettings.dtd)
     locale/browser/preferences/translation.dtd        (%chrome/browser/preferences/translation.dtd)
     locale/browser/syncBrand.dtd                (%chrome/browser/syncBrand.dtd)
     locale/browser/syncSetup.properties         (%chrome/browser/syncSetup.properties)
 % resource search-plugins chrome://browser/locale/searchplugins/
 #if BUILD_FASTER
     locale/browser/searchplugins/               (searchplugins/*.xml)
     locale/browser/searchplugins/list.json      (search/list.json)
 #else