diff --git a/browser/base/content/browser-trackingprotection.js b/browser/base/content/browser-trackingprotection.js
index 2c13f088062..ffc0443c8fb 100644
--- a/browser/base/content/browser-trackingprotection.js
+++ b/browser/base/content/browser-trackingprotection.js
@@ -184,7 +184,6 @@ var TrackingProtection = {
   },
 
   showIntroPanel: Task.async(function*() {
-    let mm = gBrowser.selectedBrowser.messageManager;
     let brandBundle = document.getElementById("bundle_brand");
     let brandShortName = brandBundle.getString("brandShortName");
 
@@ -219,7 +218,7 @@ var TrackingProtection = {
 
     let panelTarget = yield UITour.getTarget(window, "trackingProtection");
     UITour.initForBrowser(gBrowser.selectedBrowser, window);
-    UITour.showInfo(window, mm, panelTarget,
+    UITour.showInfo(window, panelTarget,
                     gNavigatorBundle.getString("trackingProtection.intro.title"),
                     gNavigatorBundle.getFormattedString("trackingProtection.intro.description",
                                                         [brandShortName]),
diff --git a/browser/base/content/nsContextMenu.js b/browser/base/content/nsContextMenu.js
index 30f13c76678..d092ccbf241 100644
--- a/browser/base/content/nsContextMenu.js
+++ b/browser/base/content/nsContextMenu.js
@@ -1759,17 +1759,8 @@ nsContextMenu.prototype = {
       selectedText = selectedText.substr(0,truncLength) + this.ellipsis;
     }
 
-    // Use the current engine if the search bar is visible, the default
-    // engine otherwise.
-    var engineName = "";
-    var ss = Cc["@mozilla.org/browser/search-service;1"].
-             getService(Ci.nsIBrowserSearchService);
-    if (isElementVisible(BrowserSearch.searchBar))
-      engineName = ss.currentEngine.name;
-    else
-      engineName = ss.defaultEngine.name;
-
     // format "Search <engine> for <selection>" string to show in menu
+    let engineName = Services.search.currentEngine.name;
     var menuLabel = gNavigatorBundle.getFormattedString("contextMenuSearch",
                                                         [engineName,
                                                          selectedText]);
diff --git a/browser/components/extensions/ext-tabs.js b/browser/components/extensions/ext-tabs.js
index 8ae7d933cd5..f724d8f5fee 100644
--- a/browser/components/extensions/ext-tabs.js
+++ b/browser/components/extensions/ext-tabs.js
@@ -261,27 +261,21 @@ extensions.registerSchemaAPI("tabs", null, (extension, context) => {
       }).api(),
 
       create: function(createProperties, callback) {
-        if (!createProperties) {
-          createProperties = {};
-        }
-
         let url = createProperties.url || aboutNewTabService.newTabURL;
-        url = extension.baseURI.resolve(url);
+        url = context.uri.resolve(url);
 
         function createInWindow(window) {
           let tab = window.gBrowser.addTab(url);
 
           let active = true;
-          if ("active" in createProperties) {
+          if (createProperties.active !== null) {
             active = createProperties.active;
-          } else if ("selected" in createProperties) {
-            active = createProperties.selected;
           }
           if (active) {
             window.gBrowser.selectedTab = tab;
           }
 
-          if ("index" in createProperties) {
+          if (createProperties.index !== null) {
             window.gBrowser.moveTabTo(tab, createProperties.index);
           }
 
diff --git a/browser/components/extensions/test/browser/browser.ini b/browser/components/extensions/test/browser/browser.ini
index e6e16afc479..b24a926f069 100644
--- a/browser/components/extensions/test/browser/browser.ini
+++ b/browser/components/extensions/test/browser/browser.ini
@@ -24,6 +24,7 @@ support-files =
 [browser_ext_tabs_executeScript_bad.js]
 [browser_ext_tabs_query.js]
 [browser_ext_tabs_getCurrent.js]
+[browser_ext_tabs_create.js]
 [browser_ext_tabs_update.js]
 [browser_ext_tabs_onUpdated.js]
 [browser_ext_tabs_sendMessage.js]
diff --git a/browser/components/extensions/test/browser/browser_ext_tabs_create.js b/browser/components/extensions/test/browser/browser_ext_tabs_create.js
new file mode 100644
index 00000000000..c5b7ec8c64b
--- /dev/null
+++ b/browser/components/extensions/test/browser/browser_ext_tabs_create.js
@@ -0,0 +1,169 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+"use strict";
+
+add_task(function* () {
+  let tab = yield BrowserTestUtils.openNewForegroundTab(gBrowser, "about:robots");
+  gBrowser.selectedTab = tab;
+
+  // TODO: Multiple windows.
+
+  // Using pre-loaded new tab pages interferes with onUpdated events.
+  // It probably shouldn't.
+  SpecialPowers.setBoolPref("browser.newtab.preload", false);
+  registerCleanupFunction(() => {
+    SpecialPowers.clearUserPref("browser.newtab.preload");
+  });
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "permissions": ["tabs"],
+
+      "background": { "page": "bg/background.html" },
+    },
+
+    files: {
+      "bg/blank.html": `<html><head><meta charset="utf-8"></head></html>`,
+
+      "bg/background.html": `<html><head>
+        <meta charset="utf-8">
+        <script src="background.js"></script>
+      </head></html>`,
+
+      "bg/background.js": function() {
+        // Wrap API methods in promise-based variants.
+        let promiseTabs = {};
+        Object.keys(browser.tabs).forEach(method => {
+          promiseTabs[method] = (...args) => {
+            return new Promise(resolve => {
+              browser.tabs[method](...args, resolve);
+            });
+          };
+        });
+
+
+        let activeTab;
+        let activeWindow;
+
+        function runTests() {
+          const DEFAULTS = {
+            index: 2,
+            windowId: activeWindow,
+            active: true,
+            pinned: false,
+            url: "about:newtab",
+          };
+
+          let tests = [
+            {
+              create: { url: "http://example.com/" },
+              result: { url: "http://example.com/" },
+            },
+            {
+              create: { url: "blank.html" },
+              result: { url: browser.runtime.getURL("bg/blank.html") },
+            },
+            {
+              create: {},
+              result: { url: "about:newtab" },
+            },
+            {
+              create: { active: false },
+              result: { active: false },
+            },
+            {
+              create: { active: true },
+              result: { active: true },
+            },
+            {
+              create: { pinned: true },
+              result: { pinned: true, index: 0 },
+            },
+            {
+              create: { pinned: true, active: true },
+              result: { pinned: true, active: true, index: 0 },
+            },
+            {
+              create: { pinned: true, active: false },
+              result: { pinned: true, active: false, index: 0 },
+            },
+            {
+              create: { index: 1 },
+              result: { index: 1 },
+            },
+            {
+              create: { index: 1, active: false },
+              result: { index: 1, active: false },
+            },
+            {
+              create: { windowId: activeWindow },
+              result: { windowId: activeWindow },
+            },
+          ];
+
+          function nextTest() {
+            if (!tests.length) {
+              browser.test.notifyPass("tabs.create");
+              return;
+            }
+
+            let test = tests.shift();
+            let expected = Object.assign({}, DEFAULTS, test.result);
+
+            browser.test.log(`Testing tabs.create(${JSON.stringify(test.create)}), expecting ${JSON.stringify(test.result)}`);
+
+            let tabId;
+            let updatedPromise = new Promise(resolve => {
+              let onUpdated = (changedTabId, changed) => {
+                if (changedTabId === tabId && changed.url) {
+                  browser.tabs.onUpdated.removeListener(onUpdated);
+                  resolve(changed.url);
+                }
+              };
+              browser.tabs.onUpdated.addListener(onUpdated);
+            });
+
+            promiseTabs.create(test.create).then(tab => {
+              tabId = tab.id;
+
+              for (let key of Object.keys(expected)) {
+                if (key === "url") {
+                  // FIXME: This doesn't get updated until later in the load cycle.
+                  continue;
+                }
+
+                browser.test.assertEq(expected[key], tab[key], `Expected value for tab.${key}`);
+              }
+
+              return updatedPromise;
+            }).then(url => {
+              browser.test.assertEq(expected.url, url, `Expected value for tab.url`);
+
+              return promiseTabs.remove(tabId);
+            }).then(() => {
+              return promiseTabs.update(activeTab, { active: true });
+            }).then(() => {
+              nextTest();
+            });
+          }
+
+          nextTest();
+        }
+
+        browser.tabs.query({ active: true, currentWindow: true }, tabs => {
+          activeTab = tabs[0].id;
+          activeWindow = tabs[0].windowId;
+
+          runTests();
+        });
+      },
+    },
+  });
+
+  yield extension.startup();
+  yield extension.awaitFinish("tabs.create");
+  yield extension.unload();
+
+  yield BrowserTestUtils.removeTab(tab);
+});
+
diff --git a/browser/components/nsBrowserContentHandler.js b/browser/components/nsBrowserContentHandler.js
index e89004dcb09..93aa8c9cf1e 100644
--- a/browser/components/nsBrowserContentHandler.js
+++ b/browser/components/nsBrowserContentHandler.js
@@ -38,7 +38,6 @@ const nsIWebNavigation       = Components.interfaces.nsIWebNavigation;
 const nsIWindowMediator      = Components.interfaces.nsIWindowMediator;
 const nsIWindowWatcher       = Components.interfaces.nsIWindowWatcher;
 const nsIWebNavigationInfo   = Components.interfaces.nsIWebNavigationInfo;
-const nsIBrowserSearchService = Components.interfaces.nsIBrowserSearchService;
 const nsICommandLineValidator = Components.interfaces.nsICommandLineValidator;
 
 const NS_BINDING_ABORTED = Components.results.NS_BINDING_ABORTED;
@@ -262,10 +261,7 @@ function logSystemBasedSearch(engine) {
 }
 
 function doSearch(searchTerm, cmdLine) {
-  var ss = Components.classes["@mozilla.org/browser/search-service;1"]
-                     .getService(nsIBrowserSearchService);
-
-  var engine = ss.defaultEngine;
+  var engine = Services.search.defaultEngine;
   logSystemBasedSearch(engine);
 
   var submission = engine.getSubmission(searchTerm, null, "system");
@@ -796,9 +792,7 @@ nsDefaultCommandLineHandler.prototype = {
             }
             if (allowedParams.indexOf(formParam) != -1) {
               var term = params.get("q");
-              var ss = Components.classes["@mozilla.org/browser/search-service;1"]
-                                 .getService(nsIBrowserSearchService);
-              var engine = ss.defaultEngine;
+              var engine = Services.search.defaultEngine;
               logSystemBasedSearch(engine);
               var submission = engine.getSubmission(term, null, "system");
               uri = submission.uri;
diff --git a/browser/components/nsBrowserGlue.js b/browser/components/nsBrowserGlue.js
index d49586ceaeb..3117adce82b 100644
--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -446,30 +446,6 @@ BrowserGlue.prototype = {
           Preferences.set("browser.search.hiddenOneOffs",
                           hiddenList.join(","));
         }
-
-        if (data != "engine-default" && data != "engine-current") {
-          break;
-        }
-        // Enforce that the search service's defaultEngine is always equal to
-        // its currentEngine. The search service will notify us any time either
-        // of them are changed (either by directly setting the relevant prefs,
-        // i.e. if add-ons try to change this directly, or if the
-        // nsIBrowserSearchService setters are called).
-        // No need to initialize the search service, since it's guaranteed to be
-        // initialized already when this notification fires.
-        let ss = Services.search;
-        if (ss.currentEngine.name == ss.defaultEngine.name)
-          return;
-        if (data == "engine-current")
-          ss.defaultEngine = ss.currentEngine;
-        else
-          ss.currentEngine = ss.defaultEngine;
-        break;
-      case "browser-search-service":
-        if (data != "init-complete")
-          return;
-        Services.obs.removeObserver(this, "browser-search-service");
-        this._syncSearchEngines();
         break;
 #ifdef NIGHTLY_BUILD
       case "nsPref:changed":
@@ -568,16 +544,6 @@ BrowserGlue.prototype = {
     }
   },
 
-  _syncSearchEngines: function () {
-    // Only do this if the search service is already initialized. This function
-    // gets called in finalUIStartup and from a browser-search-service observer,
-    // to catch both cases (search service initialization occurring before and
-    // after final-ui-startup)
-    if (Services.search.isInitialized) {
-      Services.search.defaultEngine = Services.search.currentEngine;
-    }
-  },
-
   // initialization (called on application startup)
   _init: function BG__init() {
     let os = Services.obs;
@@ -609,7 +575,6 @@ BrowserGlue.prototype = {
     os.addObserver(this, "keyword-search", false);
 #endif
     os.addObserver(this, "browser-search-engine-modified", false);
-    os.addObserver(this, "browser-search-service", false);
     os.addObserver(this, "restart-in-safe-mode", false);
     os.addObserver(this, "flash-plugin-hang", false);
     os.addObserver(this, "xpi-signature-changed", false);
@@ -669,10 +634,6 @@ BrowserGlue.prototype = {
     os.removeObserver(this, "keyword-search");
 #endif
     os.removeObserver(this, "browser-search-engine-modified");
-    try {
-      os.removeObserver(this, "browser-search-service");
-      // may have already been removed by the observer
-    } catch (ex) {}
 #ifdef NIGHTLY_BUILD
     Services.prefs.removeObserver(POLARIS_ENABLED, this);
 #endif
@@ -823,8 +784,6 @@ BrowserGlue.prototype = {
     // handle any UI migration
     this._migrateUI();
 
-    this._syncSearchEngines();
-
     WebappManager.init();
     PageThumbs.init();
 #ifdef NIGHTLY_BUILD
diff --git a/browser/components/preferences/donottrack.xul b/browser/components/preferences/donottrack.xul
new file mode 100644
index 00000000000..40f0aacebbe
--- /dev/null
+++ b/browser/components/preferences/donottrack.xul
@@ -0,0 +1,35 @@
+<?xml version="1.0"?>
+
+<!-- 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/. -->
+
+<?xml-stylesheet href="chrome://global/skin/"?>
+<?xml-stylesheet href="chrome://browser/skin/preferences/preferences.css"?>
+
+<!DOCTYPE prefwindow SYSTEM "chrome://browser/locale/preferences/donottrack.dtd" >
+
+<prefwindow id="DoNotTrackDialog" type="child"
+            xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+            xmlns:html="http://www.w3.org/1999/xhtml"
+            title="&window.title;"
+            style="width: &window.width;; height: &window.height;;"
+            dlgbuttons="accept,cancel">
+  <prefpane>
+    <preferences>
+      <preference id="privacy.donottrackheader.enabled"
+                  name="privacy.donottrackheader.enabled"
+                  type="bool"/>
+    </preferences>
+    <hbox align="center" pack="start">
+      <!-- Work around focus ring not showing properly. -->
+      <spacer style="width: 1em;"/>
+      <checkbox label="&doNotTrackCheckbox.label;"
+                accesskey="&doNotTrackCheckbox.accesskey;"
+                preference="privacy.donottrackheader.enabled"/>
+      <label class="text-link doNotTrackLearnMore"
+             value="&doNotTrackLearnMore.label;"
+             href="https://www.mozilla.org/dnt"/>
+    </hbox>
+  </prefpane>
+</prefwindow>
diff --git a/browser/components/preferences/in-content/privacy.js b/browser/components/preferences/in-content/privacy.js
index 3ec0afe9c27..3f5cfeec3d8 100644
--- a/browser/components/preferences/in-content/privacy.js
+++ b/browser/components/preferences/in-content/privacy.js
@@ -30,7 +30,10 @@ var gPrivacyPane = {
     let url = Services.urlFormatter.formatURLPref("app.support.baseURL") + "tracking-protection";
     link.setAttribute("href", url);
 
+    this.trackingProtectionReadPrefs();
+
     document.getElementById("trackingprotectionbox").hidden = false;
+    document.getElementById("trackingprotectionpbmbox").hidden = true;
   },
 #endif
 
@@ -108,6 +111,10 @@ var gPrivacyPane = {
       gPrivacyPane.clearPrivateDataNow(true);
       return false;
     });
+    setEventListener("doNotTrackSettings", "click", function () {
+      gPrivacyPane.showDoNotTrackSettings();
+      return false;
+    });
     setEventListener("privateBrowsingAutoStart", "command",
                      gPrivacyPane.updateAutostart);
     setEventListener("cookieExceptions", "command",
@@ -116,8 +123,54 @@ var gPrivacyPane = {
                      gPrivacyPane.showCookies);
     setEventListener("clearDataSettings", "command",
                      gPrivacyPane.showClearPrivateDataSettings);
+    setEventListener("trackingProtectionRadioGroup", "command",
+                     gPrivacyPane.trackingProtectionWritePrefs);
+    setEventListener("trackingProtectionExceptions", "command",
+                     gPrivacyPane.showTrackingProtectionExceptions);
     setEventListener("changeBlockList", "command",
                      gPrivacyPane.showBlockLists);
+    setEventListener("changeBlockListPBM", "command",
+                     gPrivacyPane.showBlockLists);
+  },
+
+  // TRACKING PROTECTION MODE
+
+  /**
+   * Selects the right item of the Tracking Protection radiogroup.
+   */
+  trackingProtectionReadPrefs() {
+    let enabledPref = document.getElementById("privacy.trackingprotection.enabled");
+    let pbmPref = document.getElementById("privacy.trackingprotection.pbmode.enabled");
+    let radiogroup = document.getElementById("trackingProtectionRadioGroup");
+
+    // Global enable takes precedence over enabled in Private Browsing.
+    radiogroup.value = enabledPref.value ? "always" :
+                       pbmPref.value ? "private" :
+                       "never";
+  },
+
+  /**
+   * Sets the pref values based on the selected item of the radiogroup.
+   */
+  trackingProtectionWritePrefs() {
+    let enabledPref = document.getElementById("privacy.trackingprotection.enabled");
+    let pbmPref = document.getElementById("privacy.trackingprotection.pbmode.enabled");
+    let radiogroup = document.getElementById("trackingProtectionRadioGroup");
+
+    switch (radiogroup.value) {
+      case "always":
+        enabledPref.value = true;
+        pbmPref.value = true;
+        break;
+      case "private":
+        enabledPref.value = false;
+        pbmPref.value = true;
+        break;
+      case "never":
+        enabledPref.value = false;
+        pbmPref.value = false;
+        break;
+    }
   },
 
   // HISTORY MODE
@@ -371,6 +424,21 @@ var gPrivacyPane = {
       this._shouldPromptForRestart = true;
   },
 
+  /**
+   * Displays fine-grained, per-site preferences for tracking protection.
+   */
+  showTrackingProtectionExceptions() {
+    let bundlePreferences = document.getElementById("bundlePreferences");
+    let params = {
+      permissionType: "trackingprotection",
+      hideStatusColumn: true,
+      windowTitle: bundlePreferences.getString("trackingprotectionpermissionstitle"),
+      introText: bundlePreferences.getString("trackingprotectionpermissionstext"),
+    };
+    gSubDialog.open("chrome://browser/content/preferences/permissions.xul",
+                    null, params);
+  },
+
   /**
    * Displays the available block lists for tracking protection.
    */
@@ -386,6 +454,14 @@ var gPrivacyPane = {
                     null, params);
   },
 
+  /**
+   * Displays the Do Not Track settings dialog.
+   */
+  showDoNotTrackSettings() {
+    gSubDialog.open("chrome://browser/content/preferences/donottrack.xul",
+                    "resizable=no");
+  },
+
   // HISTORY
 
   /*
diff --git a/browser/components/preferences/in-content/privacy.xul b/browser/components/preferences/in-content/privacy.xul
index beb1800d289..3f9de6839ce 100644
--- a/browser/components/preferences/in-content/privacy.xul
+++ b/browser/components/preferences/in-content/privacy.xul
@@ -10,9 +10,6 @@
 <preferences id="privacyPreferences" hidden="true" data-category="panePrivacy">
 
   <!-- Tracking -->
-  <preference id="privacy.donottrackheader.enabled"
-              name="privacy.donottrackheader.enabled"
-              type="bool"/>
   <preference id="privacy.trackingprotection.enabled"
               name="privacy.trackingprotection.enabled"
               type="bool"/>
@@ -30,6 +27,9 @@
   <preference id="pref.privacy.disable_button.change_blocklist"
               name="pref.privacy.disable_button.change_blocklist"
               type="bool"/>
+  <preference id="pref.privacy.disable_button.tracking_protection_exceptions"
+              name="pref.privacy.disable_button.tracking_protection_exceptions"
+              type="bool"/>
 
   <!-- Location Bar -->
   <preference id="browser.urlbar.autocomplete.enabled"
@@ -87,32 +87,40 @@
 
 <!-- Tracking -->
 <groupbox id="trackingGroup" data-category="panePrivacy" hidden="true">
-  <caption><label>&tracking.label;</label></caption>
-  <vbox>
-    <hbox align="center">
-      <checkbox id="privacyDoNotTrackCheckbox"
-                label="&dntTrackingNotOkay4.label;"
-                accesskey="&dntTrackingNotOkay4.accesskey;"
-                preference="privacy.donottrackheader.enabled"/>
-      <label id="doNotTrackInfo"
-             class="text-link"
-             href="https://www.mozilla.org/dnt">
-        &doNotTrackInfo.label;
-      </label>
-    </hbox>
-  </vbox>
   <vbox id="trackingprotectionbox" hidden="true">
-    <hbox align="center">
-      <checkbox id="trackingProtection"
-                preference="privacy.trackingprotection.enabled"
-                accesskey="&trackingProtection5.accesskey;"
-                label="&trackingProtection5.label;" />
-      <label id="trackingProtectionLearnMore"
-             class="text-link"
-             value="&trackingProtectionLearnMore.label;"/>
+    <hbox align="start">
+      <vbox>
+        <caption><label>&trackingProtectionHeader.label;
+          <label id="trackingProtectionLearnMore" class="text-link"
+                 value="&trackingProtectionLearnMore.label;"/>
+        </label></caption>
+        <radiogroup id="trackingProtectionRadioGroup">
+          <radio value="always"
+                 label="&trackingProtectionAlways.label;"
+                 accesskey="&trackingProtectionAlways.accesskey;"/>
+          <radio value="private"
+                 label="&trackingProtectionPrivate.label;"
+                 accesskey="&trackingProtectionPrivate.accesskey;"/>
+          <radio value="never"
+                 label="&trackingProtectionNever.label;"
+                 accesskey="&trackingProtectionNever.accesskey;"/>
+        </radiogroup>
+      </vbox>
+      <spacer flex="1" />
+      <vbox>
+        <button id="trackingProtectionExceptions"
+                label="&trackingProtectionExceptions.label;"
+                accesskey="&trackingProtectionExceptions.accesskey;"
+                preference="pref.privacy.disable_button.tracking_protection_exceptions"/>
+        <button id="changeBlockList"
+                label="&changeBlockList.label;"
+                accesskey="&changeBlockList.accesskey;"
+                preference="pref.privacy.disable_button.change_blocklist"/>
+      </vbox>
     </hbox>
   </vbox>
   <vbox id="trackingprotectionpbmbox">
+    <caption><label>&tracking.label;</label></caption>
     <hbox align="center">
       <checkbox id="trackingProtectionPBM"
                 preference="privacy.trackingprotection.pbmode.enabled"
@@ -122,11 +130,16 @@
              class="text-link"
              value="&trackingProtectionPBMLearnMore.label;"/>
       <spacer flex="1" />
-      <button id="changeBlockList"
+      <button id="changeBlockListPBM"
               label="&changeBlockList.label;" accesskey="&changeBlockList.accesskey;"
               preference="pref.privacy.disable_button.change_blocklist"/>
     </hbox>
   </vbox>
+  <vbox>
+    <description>&doNotTrack.pre.label;<html:a
+    class="inline-link" id="doNotTrackSettings" href="#"
+    >&doNotTrack.settings.label;</html:a>&doNotTrack.post.label;</description>
+  </vbox>
 </groupbox>
 
 <!-- History -->
diff --git a/browser/components/preferences/in-content/subdialogs.js b/browser/components/preferences/in-content/subdialogs.js
index ed17cf7ca68..ec1b68fcc8e 100644
--- a/browser/components/preferences/in-content/subdialogs.js
+++ b/browser/components/preferences/in-content/subdialogs.js
@@ -97,7 +97,7 @@ var gSubDialog = {
   handleEvent: function(aEvent) {
     switch (aEvent.type) {
       case "command":
-        this.close(aEvent);
+        this._frame.contentWindow.close();
         break;
       case "dialogclosing":
         this._onDialogClosing(aEvent);
@@ -127,7 +127,7 @@ var gSubDialog = {
 
   _onUnload: function(aEvent) {
     if (aEvent.target.location.href == this._openedURL) {
-      this.close(this._closingEvent);
+      this._frame.contentWindow.close();
     }
   },
 
diff --git a/browser/components/preferences/in-content/tests/browser.ini b/browser/components/preferences/in-content/tests/browser.ini
index b15d5d29b1f..7d8439f7156 100644
--- a/browser/components/preferences/in-content/tests/browser.ini
+++ b/browser/components/preferences/in-content/tests/browser.ini
@@ -32,7 +32,6 @@ skip-if = e10s # Bug ?????? -  "leaked until shutdown [nsGlobalWindow #99 about:
 [browser_sanitizeOnShutdown_prefLocked.js]
 [browser_searchsuggestions.js]
 [browser_subdialogs.js]
-skip-if = e10s # Bug 1087114
 support-files = subdialog.xul
 [browser_telemetry.js]
 # Skip this test on Android and B2G as FHR and Telemetry are separate systems there.
diff --git a/browser/components/preferences/in-content/tests/browser_subdialogs.js b/browser/components/preferences/in-content/tests/browser_subdialogs.js
index 1e9e5693251..c49ff0bde48 100644
--- a/browser/components/preferences/in-content/tests/browser_subdialogs.js
+++ b/browser/components/preferences/in-content/tests/browser_subdialogs.js
@@ -7,268 +7,265 @@
  * Tests for the sub-dialog infrastructure, not for actual sub-dialog functionality.
  */
 
-var gTeardownAfterClose = false;
 const gDialogURL = getRootDirectory(gTestPath) + "subdialog.xul";
 
-function test() {
-  waitForExplicitFinish();
-  open_preferences((win) => {
-    Task.spawn(function () {
-      for (let test of gTests) {
-        info("STARTING TEST: " + test.desc);
-        try {
-          yield test.run();
-        } finally {
-          if (test.teardown) {
-            yield test.teardown();
-          }
-        }
+function* open_subdialog_and_test_generic_start_state(browser, domcontentloadedFn) {
+  let domcontentloadedFnStr = domcontentloadedFn ?
+    "(" + domcontentloadedFn.toString() + ")()" :
+    "";
+  return ContentTask.spawn(browser, {gDialogURL, domcontentloadedFnStr}, function*(args) {
+    let {gDialogURL, domcontentloadedFnStr} = args;
+    let rv = { acceptCount: 0 };
+    let win = content.window;
+    let subdialog = win.gSubDialog;
+    subdialog.open(gDialogURL, null, rv);
+
+    info("waiting for subdialog DOMFrameContentLoaded");
+    yield ContentTaskUtils.waitForEvent(win, "DOMFrameContentLoaded", true);
+    let result;
+    if (domcontentloadedFnStr) {
+      result = eval(domcontentloadedFnStr);
+    }
+
+    info("waiting for subdialog load");
+    yield ContentTaskUtils.waitForEvent(subdialog._frame, "load");
+    info("subdialog window is loaded");
+
+    let expectedStyleSheetURLs = subdialog._injectedStyleSheets.slice(0);
+    for (let styleSheet of subdialog._frame.contentDocument.styleSheets) {
+      let index = expectedStyleSheetURLs.indexOf(styleSheet.href);
+      if (index >= 0) {
+        expectedStyleSheetURLs.splice(index, 1);
       }
-    });
+    }
+
+    ok(!!subdialog._frame.contentWindow, "The dialog should be non-null");
+    isnot(subdialog._frame.contentWindow.location.toString(), "about:blank",
+      "Subdialog URL should not be about:blank");
+    is(win.getComputedStyle(subdialog._overlay, "").visibility, "visible",
+      "Overlay should be visible");
+    is(expectedStyleSheetURLs.length, 0,
+      "No stylesheets that were expected are missing");
+    return result;
   });
 }
 
-var gTests = [{
-  desc: "Check titlebar, focus, return value, title changes, and accepting",
-  run: function* () {
-    let rv = { acceptCount: 0 };
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, rv,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-    let dialog = yield dialogPromise;
+function* close_subdialog_and_test_generic_end_state(browser, closingFn, closingButton, acceptCount, options) {
+  let dialogclosingPromise = ContentTask.spawn(browser, {closingButton, acceptCount}, function*(expectations) {
+    let win = content.window;
+    let subdialog = win.gSubDialog;
+    let frame = subdialog._frame;
+    info("waiting for dialogclosing");
+    let closingEvent =
+      yield ContentTaskUtils.waitForEvent(frame.contentWindow, "dialogclosing");
+    let actualAcceptCount = frame.contentWindow.arguments &&
+                            frame.contentWindow.arguments[0].acceptCount;
 
-    // Check focus is in the textbox
-    is(dialog.document.activeElement.value, "Default text", "Textbox with correct text is focused");
+    info("waiting for about:blank load");
+    yield ContentTaskUtils.waitForEvent(frame, "load");
 
-    // Titlebar
-    is(content.document.getElementById("dialogTitle").textContent, "Sample sub-dialog",
-      "Dialog title should be correct initially");
-    let receivedEvent = waitForEvent(gBrowser.selectedBrowser, "DOMTitleChanged");
-    dialog.document.title = "Updated title";
-    // Wait for the title change listener
-    yield receivedEvent;
-    is(content.document.getElementById("dialogTitle").textContent, "Updated title",
-      "Dialog title should be updated with changes");
+    isnot(win.getComputedStyle(subdialog._overlay, "").visibility, "visible",
+      "overlay is not visible");
+    is(frame.getAttribute("style"), "", "inline styles should be cleared");
+    is(frame.contentWindow.location.href.toString(), "about:blank",
+      "sub-dialog should be unloaded");
+    is(closingEvent.detail.button, expectations.closingButton,
+      "closing event should indicate button was '" + expectations.closingButton + "'");
+    is(actualAcceptCount, expectations.acceptCount,
+      "should be 1 if accepted, 0 if canceled, undefined if closed w/out button");
+  });
 
-    let closingPromise = promiseDialogClosing(dialog);
-
-    // Accept the dialog
-    dialog.document.documentElement.acceptDialog();
-    let closingEvent = yield closingPromise;
-    is(closingEvent.detail.button, "accept", "closing event should indicate button was 'accept'");
-
-    yield deferredClose.promise;
-    is(rv.acceptCount, 1, "return value should have been updated");
-  },
-},
-{
-  desc: "Check canceling the dialog",
-  run: function* () {
-    let rv = { acceptCount: 0 };
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, rv,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-    let dialog = yield dialogPromise;
-
-    let closingPromise = promiseDialogClosing(dialog);
-
-    info("cancelling the dialog");
-    dialog.document.documentElement.cancelDialog();
-
-    let closingEvent = yield closingPromise;
-    is(closingEvent.detail.button, "cancel", "closing event should indicate button was 'cancel'");
-
-    yield deferredClose.promise;
-    is(rv.acceptCount, 0, "return value should NOT have been updated");
-  },
-},
-{
-  desc: "Check window.close on the dialog",
-  run: function* () {
-    let rv = { acceptCount: 0 };
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, rv,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-    let dialog = yield dialogPromise;
-
-    let closingPromise = promiseDialogClosing(dialog);
-    info("window.close called on the dialog");
-    dialog.window.close();
-
-    let closingEvent = yield closingPromise;
-    is(closingEvent.detail.button, null, "closing event should indicate no button was clicked");
-
-    yield deferredClose.promise;
-    is(rv.acceptCount, 0, "return value should NOT have been updated");
-  },
-},
-{
-  desc: "Check clicking the close button on the dialog",
-  run: function* () {
-    let rv = { acceptCount: 0 };
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, rv,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-    let dialog = yield dialogPromise;
-
-    yield EventUtils.synthesizeMouseAtCenter(content.document.getElementById("dialogClose"), {},
-                                             content.window);
-
-    yield deferredClose.promise;
-    is(rv.acceptCount, 0, "return value should NOT have been updated");
-  },
-},
-{
-  desc: "Check that 'back' navigation will close the dialog",
-  run: function* () {
-    let rv = { acceptCount: 0 };
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, rv,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-    let dialog = yield dialogPromise;
-
-    info("cancelling the dialog");
-    content.gSubDialog._frame.goBack();
-
-    yield deferredClose.promise;
-    is(rv.acceptCount, 0, "return value should NOT have been updated");
-  },
-},
-{
-  desc: "Hitting escape in the dialog",
-  run: function* () {
-    let rv = { acceptCount: 0 };
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, rv,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-    let dialog = yield dialogPromise;
-
-    EventUtils.synthesizeKey("VK_ESCAPE", {}, content.window);
-
-    yield deferredClose.promise;
-    is(rv.acceptCount, 0, "return value should NOT have been updated");
-  },
-},
-{
-  desc: "Check that width and height from the sub-dialog are used to size the <browser>",
-  run: function* () {
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, null,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-    let dialog = yield dialogPromise;
-
-    is(content.gSubDialog._frame.style.width, "32em", "Width should be set on the frame from the dialog");
-    is(content.gSubDialog._frame.style.height, "5em", "Height should be set on the frame from the dialog");
-
-    content.gSubDialog.close();
-    yield deferredClose.promise;
-  },
-},
-{
-  desc: "Check that a set width and content causing wrapping still lead to correct scrollHeight-implied height",
-  run: function* () {
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, null,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-
-    let oldHeight;
-    content.addEventListener("DOMFrameContentLoaded", function frame2Loaded() {
-      content.removeEventListener("DOMFrameContentLoaded", frame2Loaded);
-      let doc = content.gSubDialog._frame.contentDocument;
-      oldHeight = doc.documentElement.scrollHeight;
-      doc.documentElement.style.removeProperty("height");
-      doc.getElementById("desc").textContent = `
-        Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque
-        laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi
-        architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas
-        sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione
-        laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi
-        architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas
-        sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione
-        laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi
-        architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas
-        sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione
-        voluptatem sequi nesciunt.`
-      doc = null;
-    });
-
-    let dialog = yield dialogPromise;
-
-    is(content.gSubDialog._frame.style.width, "32em", "Width should be set on the frame from the dialog");
-    let docEl = content.gSubDialog._frame.contentDocument.documentElement;
-    ok(docEl.scrollHeight > oldHeight, "Content height increased (from " + oldHeight + " to " + docEl.scrollHeight + ").");
-    is(content.gSubDialog._frame.style.height, docEl.scrollHeight + "px", "Height on the frame should be higher now");
-
-    content.gSubDialog.close();
-    yield deferredClose.promise;
-  },
-},
-{
-  desc: "Check that a dialog that is too high gets cut down to size",
-  run: function* () {
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, null,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
-
-    content.addEventListener("DOMFrameContentLoaded", function frame3Loaded() {
-      content.removeEventListener("DOMFrameContentLoaded", frame3Loaded);
-      content.gSubDialog._frame.contentDocument.documentElement.style.height = '100000px';
-    });
-
-    let dialog = yield dialogPromise;
-
-    is(content.gSubDialog._frame.style.width, "32em", "Width should be set on the frame from the dialog");
-    let newHeight = content.gSubDialog._frame.contentDocument.documentElement.scrollHeight;
-    ok(parseInt(content.gSubDialog._frame.style.height) < window.innerHeight,
-       "Height on the frame should be smaller than window's innerHeight");
-
-    content.gSubDialog.close();
-    yield deferredClose.promise;
+  if (options && options.runClosingFnOutsideOfContentTask) {
+    yield closingFn();
+  } else {
+    ContentTask.spawn(browser, null, closingFn);
   }
-},
-{
-  desc: "Check that scrollWidth and scrollHeight from the sub-dialog are used to size the <browser>",
-  run: function* () {
-    let deferredClose = Promise.defer();
-    let dialogPromise = openAndLoadSubDialog(gDialogURL, null, null,
-                                             (aEvent) => dialogClosingCallback(deferredClose, aEvent));
 
-    content.addEventListener("DOMFrameContentLoaded", function frameLoaded() {
-      content.removeEventListener("DOMFrameContentLoaded", frameLoaded);
-      content.gSubDialog._frame.contentDocument.documentElement.style.removeProperty("height");
-      content.gSubDialog._frame.contentDocument.documentElement.style.removeProperty("width");
-    });
-
-    let dialog = yield dialogPromise;
-
-    ok(content.gSubDialog._frame.style.width.endsWith("px"),
-       "Width (" + content.gSubDialog._frame.style.width + ") should be set to a px value of the scrollWidth from the dialog");
-    ok(content.gSubDialog._frame.style.height.endsWith("px"),
-       "Height (" + content.gSubDialog._frame.style.height + ") should be set to a px value of the scrollHeight from the dialog");
-
-    gTeardownAfterClose = true;
-    content.gSubDialog.close();
-    yield deferredClose.promise;
-  },
-}];
-
-function promiseDialogClosing(dialog) {
-  return waitForEvent(dialog, "dialogclosing");
+  yield dialogclosingPromise;
 }
 
-function dialogClosingCallback(aPromise, aEvent) {
-  // Wait for the close handler to unload the page
-  waitForEvent(content.gSubDialog._frame, "load", 4000).then((aEvt) => {
-    info("Load event happened: " + !(aEvt instanceof Error));
-    is_element_hidden(content.gSubDialog._overlay, "Overlay is not visible");
-    is(content.gSubDialog._frame.getAttribute("style"), "",
-       "Check that inline styles were cleared");
-    is(content.gSubDialog._frame.contentWindow.location.toString(), "about:blank",
-      "Check the sub-dialog was unloaded");
-    if (gTeardownAfterClose) {
-      content.close();
-      finish();
-    }
-    aPromise.resolve();
-  }, Cu.reportError);
-}
+let tab;
+
+add_task(function* test_initialize() {
+  tab = yield BrowserTestUtils.openNewForegroundTab(gBrowser, "about:preferences");
+});
+
+add_task(function* check_titlebar_focus_returnval_titlechanges_accepting() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser);
+
+  let domtitlechangedPromise = BrowserTestUtils.waitForEvent(tab.linkedBrowser, "DOMTitleChanged");
+  yield ContentTask.spawn(tab.linkedBrowser, null, function*() {
+    let dialog = content.window.gSubDialog._frame.contentWindow;
+    let dialogTitleElement = content.document.getElementById("dialogTitle");
+    is(dialogTitleElement.textContent, "Sample sub-dialog",
+       "Title should be correct initially");
+    is(dialog.document.activeElement.value, "Default text",
+       "Textbox with correct text is focused");
+    dialog.document.title = "Updated title";
+  });
+
+  info("waiting for DOMTitleChanged event");
+  yield domtitlechangedPromise;
+
+  ContentTask.spawn(tab.linkedBrowser, null, function*() {
+    let dialogTitleElement = content.document.getElementById("dialogTitle");
+    is(dialogTitleElement.textContent, "Updated title", "subdialog should have updated title");
+  });
+
+  // Accept the dialog
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { content.window.gSubDialog._frame.contentDocument.documentElement.acceptDialog(); },
+    "accept", 1);
+});
+
+add_task(function* check_canceling_dialog() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser);
+
+  info("canceling the dialog");
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { content.window.gSubDialog._frame.contentDocument.documentElement.cancelDialog(); },
+    "cancel", 0);
+});
+
+add_task(function* window_close_on_dialog() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser);
+
+  info("canceling the dialog");
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { content.window.gSubDialog._frame.contentWindow.window.close(); },
+    null, 0);
+});
+
+add_task(function* click_close_button_on_dialog() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser);
+
+  info("canceling the dialog");
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { return BrowserTestUtils.synthesizeMouseAtCenter("#dialogClose", {}, tab.linkedBrowser); },
+    null, 0, {runClosingFnOutsideOfContentTask: true});
+});
+
+add_task(function* back_navigation_on_subdialog_should_close_dialog() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser);
+
+  info("canceling the dialog");
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { content.window.gSubDialog._frame.goBack(); },
+    null, undefined);
+});
+
+add_task(function* back_navigation_on_browser_tab_should_close_dialog() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser);
+
+  info("canceling the dialog");
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { tab.linkedBrowser.goBack(); },
+    null, undefined, {runClosingFnOutsideOfContentTask: true});
+});
+
+add_task(function* escape_should_close_dialog() {
+  todo(false, "BrowserTestUtils.sendChar('VK_ESCAPE') triggers " +
+              "'can't access dead object' on `navigator` in this test. " +
+              "See bug 1238065.")
+  return;
+
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser);
+
+  info("canceling the dialog");
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { return BrowserTestUtils.sendChar("VK_ESCAPE", tab.linkedBrowser); },
+    null, undefined, {runClosingFnOutsideOfContentTask: true});
+});
+
+add_task(function* correct_width_and_height_should_be_used_for_dialog() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser);
+
+  yield ContentTask.spawn(tab.linkedBrowser, null, function*() {
+    let frameStyle = content.window.gSubDialog._frame.style;
+    is(frameStyle.width, "32em", "Width should be set on the frame from the dialog");
+    is(frameStyle.height, "5em", "Height should be set on the frame from the dialog");
+  });
+
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { content.window.gSubDialog._frame.contentWindow.window.close(); },
+    null, 0);
+});
+
+add_task(function* wrapped_text_in_dialog_should_have_expected_scrollHeight() {
+  let oldHeight = yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser, function domcontentloadedFn() {
+    let frame = content.window.gSubDialog._frame;
+    let doc = frame.contentDocument;
+    let oldHeight = doc.documentElement.scrollHeight;
+    doc.documentElement.style.removeProperty("height");
+    doc.getElementById("desc").textContent = `
+      Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque
+      laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi
+      architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas
+      sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione
+      laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi
+      architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas
+      sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione
+      laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi
+      architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas
+      sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione
+      voluptatem sequi nesciunt.`
+    return oldHeight;
+  });
+
+  yield ContentTask.spawn(tab.linkedBrowser, oldHeight, function*(oldHeight) {
+    let frame = content.window.gSubDialog._frame;
+    let docEl = frame.contentDocument.documentElement;
+    is(frame.style.width, "32em",
+      "Width should be set on the frame from the dialog");
+    ok(docEl.scrollHeight > oldHeight,
+      "Content height increased (from " + oldHeight + " to " + docEl.scrollHeight + ").");
+    is(frame.style.height, docEl.scrollHeight + "px",
+      "Height on the frame should be higher now");
+  });
+
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { content.window.gSubDialog._frame.contentWindow.window.close(); },
+    null, 0);
+});
+
+add_task(function* dialog_too_tall_should_get_reduced_in_height() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser, function domcontentloadedFn() {
+    let frame = content.window.gSubDialog._frame;
+    frame.contentDocument.documentElement.style.height = '100000px';
+  });
+
+  yield ContentTask.spawn(tab.linkedBrowser, null, function*() {
+    let frame = content.window.gSubDialog._frame;
+    is(frame.style.width, "32em", "Width should be set on the frame from the dialog");
+    ok(parseInt(frame.style.height) < content.window.innerHeight,
+       "Height on the frame should be smaller than window's innerHeight");
+  });
+
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { content.window.gSubDialog._frame.contentWindow.window.close(); },
+    null, 0);
+});
+
+add_task(function* scrollWidth_and_scrollHeight_from_subdialog_should_size_the_browser() {
+  yield open_subdialog_and_test_generic_start_state(tab.linkedBrowser, function domcontentloadedFn() {
+    let frame = content.window.gSubDialog._frame;
+    frame.contentDocument.documentElement.style.removeProperty("height");
+    frame.contentDocument.documentElement.style.removeProperty("width");
+  });
+
+  yield ContentTask.spawn(tab.linkedBrowser, null, function*() {
+    let frame = content.window.gSubDialog._frame;
+    ok(frame.style.width.endsWith("px"),
+       "Width (" + frame.style.width + ") should be set to a px value of the scrollWidth from the dialog");
+    ok(frame.style.height.endsWith("px"),
+       "Height (" + frame.style.height + ") should be set to a px value of the scrollHeight from the dialog");
+  });
+
+  yield close_subdialog_and_test_generic_end_state(tab.linkedBrowser,
+    function() { content.window.gSubDialog._frame.contentWindow.window.close(); },
+    null, 0);
+});
+
+add_task(function* test_shutdown() {
+  gBrowser.removeTab(tab);
+});
diff --git a/browser/components/preferences/jar.mn b/browser/components/preferences/jar.mn
index c0216394ef8..20fa9db41f9 100644
--- a/browser/components/preferences/jar.mn
+++ b/browser/components/preferences/jar.mn
@@ -12,6 +12,7 @@ browser.jar:
 *   content/browser/preferences/cookies.js
 *   content/browser/preferences/connection.xul
     content/browser/preferences/connection.js
+    content/browser/preferences/donottrack.xul
 *   content/browser/preferences/fonts.xul
     content/browser/preferences/fonts.js
     content/browser/preferences/handlers.xml
diff --git a/browser/components/preferences/permissions.js b/browser/components/preferences/permissions.js
index 3a19a0612af..1957f6fd79e 100644
--- a/browser/components/preferences/permissions.js
+++ b/browser/components/preferences/permissions.js
@@ -249,6 +249,10 @@ var gPermissionManager = {
     var urlLabel = document.getElementById("urlLabel");
     urlLabel.hidden = !urlFieldVisible;
 
+    if (aParams.hideStatusColumn) {
+      document.getElementById("statusCol").hidden = true;
+    }
+
     let treecols = document.getElementsByTagName("treecols")[0];
     treecols.addEventListener("click", event => {
       if (event.target.nodeName != "treecol" || event.button != 0) {
diff --git a/browser/components/search/content/search.xml b/browser/components/search/content/search.xml
index 564e0269ade..5dae5678eeb 100644
--- a/browser/components/search/content/search.xml
+++ b/browser/components/search/content/search.xml
@@ -130,8 +130,7 @@
 
       <property name="currentEngine">
         <setter><![CDATA[
-          let ss = Services.search;
-          ss.defaultEngine = ss.currentEngine = val;
+          Services.search.currentEngine = val;
           return val;
         ]]></setter>
         <getter><![CDATA[
diff --git a/browser/components/uitour/UITour.jsm b/browser/components/uitour/UITour.jsm
index bdd3278827c..b797a23eac6 100644
--- a/browser/components/uitour/UITour.jsm
+++ b/browser/components/uitour/UITour.jsm
@@ -530,13 +530,18 @@ this.UITour = {
           }
 
           let infoOptions = {};
+          if (typeof data.closeButtonCallbackID == "string") {
+            infoOptions.closeButtonCallback = () => {
+              this.sendPageCallback(messageManager, data.closeButtonCallbackID);
+            };
+          }
+          if (typeof data.targetCallbackID == "string") {
+            infoOptions.targetCallback = details => {
+              this.sendPageCallback(messageManager, data.targetCallbackID, details);
+            };
+          }
 
-          if (typeof data.closeButtonCallbackID == "string")
-            infoOptions.closeButtonCallbackID = data.closeButtonCallbackID;
-          if (typeof data.targetCallbackID == "string")
-            infoOptions.targetCallbackID = data.targetCallbackID;
-
-          this.showInfo(window, messageManager, target, data.title, data.text, iconURL, buttons, infoOptions);
+          this.showInfo(window, target, data.title, data.text, iconURL, buttons, infoOptions);
         }).catch(log.error);
         break;
       }
@@ -1395,17 +1400,17 @@ this.UITour = {
    * Show an info panel.
    *
    * @param {ChromeWindow} aChromeWindow
-   * @param {nsIMessageSender} aMessageManager
    * @param {Node}     aAnchor
    * @param {String}   [aTitle=""]
    * @param {String}   [aDescription=""]
    * @param {String}   [aIconURL=""]
    * @param {Object[]} [aButtons=[]]
    * @param {Object}   [aOptions={}]
-   * @param {String}   [aOptions.closeButtonCallbackID]
+   * @param {String}   [aOptions.closeButtonCallback]
+   * @param {String}   [aOptions.targetCallback]
    */
-  showInfo: function(aChromeWindow, aMessageManager, aAnchor, aTitle = "", aDescription = "", aIconURL = "",
-                     aButtons = [], aOptions = {}) {
+  showInfo(aChromeWindow, aAnchor, aTitle = "", aDescription = "",
+           aIconURL = "", aButtons = [], aOptions = {}) {
     function showInfoPanel(aAnchorEl) {
       aAnchorEl.focus();
 
@@ -1461,8 +1466,9 @@ this.UITour = {
       let tooltipClose = document.getElementById("UITourTooltipClose");
       let closeButtonCallback = (event) => {
         this.hideInfo(document.defaultView);
-        if (aOptions && aOptions.closeButtonCallbackID)
-          this.sendPageCallback(aMessageManager, aOptions.closeButtonCallbackID);
+        if (aOptions && aOptions.closeButtonCallback) {
+          aOptions.closeButtonCallback();
+        }
       };
       tooltipClose.addEventListener("command", closeButtonCallback);
 
@@ -1471,16 +1477,16 @@ this.UITour = {
           target: aAnchor.targetName,
           type: event.type,
         };
-        this.sendPageCallback(aMessageManager, aOptions.targetCallbackID, details);
+        aOptions.targetCallback(details);
       };
-      if (aOptions.targetCallbackID && aAnchor.addTargetListener) {
+      if (aOptions.targetCallback && aAnchor.addTargetListener) {
         aAnchor.addTargetListener(document, targetCallback);
       }
 
       tooltip.addEventListener("popuphiding", function tooltipHiding(event) {
         tooltip.removeEventListener("popuphiding", tooltipHiding);
         tooltipClose.removeEventListener("command", closeButtonCallback);
-        if (aOptions.targetCallbackID && aAnchor.removeTargetListener) {
+        if (aOptions.targetCallback && aAnchor.removeTargetListener) {
           aAnchor.removeTargetListener(document, targetCallback);
         }
       });
diff --git a/browser/extensions/pocket/bootstrap.js b/browser/extensions/pocket/bootstrap.js
index b53a1e4980c..7ed81ad8854 100644
--- a/browser/extensions/pocket/bootstrap.js
+++ b/browser/extensions/pocket/bootstrap.js
@@ -25,6 +25,9 @@ XPCOMUtils.defineLazyModuleGetter(this, "Pocket",
 XPCOMUtils.defineLazyGetter(this, "gPocketBundle", function() {
   return Services.strings.createBundle("chrome://pocket/locale/pocket.properties");
 });
+XPCOMUtils.defineLazyGetter(this, "gPocketStyleURI", function() {
+  return Services.io.newURI("chrome://pocket/skin/pocket.css", null, null);
+});
 
 
 const PREF_BRANCH = "extensions.pocket.";
@@ -286,10 +289,12 @@ function pktUIGetter(prop, window) {
 
 var PocketOverlay = {
   startup: function(reason) {
+    let styleSheetService = Cc["@mozilla.org/content/style-sheet-service;1"]
+                              .getService(Ci.nsIStyleSheetService);
+    this._sheetType = styleSheetService.AUTHOR_SHEET;
+    this._cachedSheet = styleSheetService.preloadSheet(gPocketStyleURI,
+                                                       this._sheetType);
     CreatePocketWidget(reason);
-    Services.obs.addObserver(this,
-                             "browser-delayed-startup-finished",
-                             false);
     CustomizableUI.addListener(this);
     PocketContextMenu.init();
     PocketReader.startup();
@@ -322,9 +327,7 @@ var PocketOverlay = {
     PocketContextMenu.shutdown();
     PocketReader.shutdown();
   },
-  observe: function(aSubject, aTopic, aData) {
-    // new browser window, initialize the "overlay"
-    let window = aSubject;
+  onWindowOpened: function(window) {
     this.setWindowScripts(window);
     this.addStyles(window);
     this.updateWindow(window);
@@ -435,21 +438,13 @@ var PocketOverlay = {
   },
 
   addStyles: function(win) {
-    let xmlPI = win.document.createProcessingInstruction("xml-stylesheet",
-        "type=\"text/css\" href=\"chrome://pocket/skin/pocket.css\"");
-    win.document.insertBefore(xmlPI, win.document.documentElement);
+    let utils = win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
+    utils.addSheet(this._cachedSheet, this._sheetType);
   },
 
   removeStyles: function(win) {
-    let el = win.document.documentElement.previousSibling;
-    while (el) {
-      if (el.nodeType == el.PROCESSING_INSTRUCTION_NODE &&
-          el.sheet && el.sheet.href == "chrome://pocket/skin/pocket.css") {
-        el.remove();
-        break;
-      }
-      el = el.previousSibling;
-    }
+    let utils = win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
+    utils.removeSheet(gPocketStyleURI, this._sheetType);
   }
 
 }
diff --git a/browser/locales/en-US/chrome/browser/preferences/donottrack.dtd b/browser/locales/en-US/chrome/browser/preferences/donottrack.dtd
new file mode 100644
index 00000000000..28d31478da8
--- /dev/null
+++ b/browser/locales/en-US/chrome/browser/preferences/donottrack.dtd
@@ -0,0 +1,12 @@
+<!-- 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/. -->
+
+<!ENTITY window.title                 "Do Not Track">
+<!ENTITY window.width                 "40em">
+<!ENTITY window.height                "8em">
+
+<!ENTITY doNotTrackCheckbox.label     "Use Do Not Track">
+<!ENTITY doNotTrackCheckbox.accesskey "U">
+
+<!ENTITY doNotTrackLearnMore.label    "Learn More">
diff --git a/browser/locales/en-US/chrome/browser/preferences/preferences.properties b/browser/locales/en-US/chrome/browser/preferences/preferences.properties
index d271336afe0..c949a553d64 100644
--- a/browser/locales/en-US/chrome/browser/preferences/preferences.properties
+++ b/browser/locales/en-US/chrome/browser/preferences/preferences.properties
@@ -19,6 +19,8 @@ acceptVeryLargeMinimumFont=Keep my changes anyway
 
 #### Permissions Manager
 
+trackingprotectionpermissionstext=You have disabled Tracking Protection on these sites.
+trackingprotectionpermissionstitle=Exceptions - Tracking Protection
 cookiepermissionstext=You can specify which websites are always or never allowed to use cookies.  Type the exact address of the site you want to manage and then click Block, Allow for Session, or Allow.
 cookiepermissionstitle=Exceptions - Cookies
 addonspermissionstext=You can specify which websites are allowed to install add-ons. Type the exact address of the site you want to allow and then click Allow.
diff --git a/browser/locales/en-US/chrome/browser/preferences/privacy.dtd b/browser/locales/en-US/chrome/browser/preferences/privacy.dtd
index cb2dce6e8e6..16a90014848 100644
--- a/browser/locales/en-US/chrome/browser/preferences/privacy.dtd
+++ b/browser/locales/en-US/chrome/browser/preferences/privacy.dtd
@@ -2,20 +2,30 @@
    - 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/. -->
 
-<!ENTITY tracking.label                 "Tracking">
+<!ENTITY  trackingProtectionHeader.label       "Use Tracking Protection">
+<!ENTITY  trackingProtectionAlways.label       "Always">
+<!ENTITY  trackingProtectionAlways.accesskey   "y">
+<!ENTITY  trackingProtectionPrivate.label      "Only in private windows">
+<!ENTITY  trackingProtectionPrivate.accesskey  "l">
+<!ENTITY  trackingProtectionNever.label        "Never">
+<!ENTITY  trackingProtectionNever.accesskey    "n">
+<!ENTITY  trackingProtectionLearnMore.label    "Learn more">
+<!ENTITY  trackingProtectionExceptions.label   "Exceptions…">
+<!ENTITY  trackingProtectionExceptions.accesskey "x">
 
-<!ENTITY dntTrackingNotOkay4.label     "Request that sites not track you">
-<!ENTITY dntTrackingNotOkay4.accesskey "n">
-<!ENTITY doNotTrackInfo.label          "Learn More">
-<!ENTITY trackingProtection5.label     "Use Tracking Protection">
-<!ENTITY trackingProtection5.accesskey "i">
-<!ENTITY trackingProtectionLearnMore.label "Learn more">
+<!ENTITY tracking.label                 "Tracking">
 <!ENTITY trackingProtectionPBM5.label         "Use Tracking Protection in Private Windows">
 <!ENTITY trackingProtectionPBM5.accesskey     "v">
 <!ENTITY trackingProtectionPBMLearnMore.label "Learn more">
 <!ENTITY changeBlockList.label          "Change Block List">
 <!ENTITY changeBlockList.accesskey      "C">
 
+<!-- LOCALIZATION NOTE (doNotTrack.pre.label): include a trailing space as needed -->
+<!-- LOCALIZATION NOTE (doNotTrack.post.label): include a starting space as needed -->
+<!ENTITY  doNotTrack.pre.label          "You can also ">
+<!ENTITY  doNotTrack.settings.label     "manage your Do Not Track settings">
+<!ENTITY  doNotTrack.post.label         ".">
+
 <!ENTITY  history.label                 "History">
 
 <!ENTITY  locationBar.label             "Location Bar">
diff --git a/browser/locales/jar.mn b/browser/locales/jar.mn
index 4d009043bc9..fd5153be82d 100644
--- a/browser/locales/jar.mn
+++ b/browser/locales/jar.mn
@@ -70,6 +70,7 @@
     locale/browser/preferences/cookies.dtd            (%chrome/browser/preferences/cookies.dtd)
     locale/browser/preferences/content.dtd            (%chrome/browser/preferences/content.dtd)
     locale/browser/preferences/connection.dtd         (%chrome/browser/preferences/connection.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/main.dtd               (%chrome/browser/preferences/main.dtd)
diff --git a/browser/modules/ReaderParent.jsm b/browser/modules/ReaderParent.jsm
index b81fca83aa9..bf8a70697cb 100644
--- a/browser/modules/ReaderParent.jsm
+++ b/browser/modules/ReaderParent.jsm
@@ -189,7 +189,7 @@ var ReaderParent = {
       } else {
         icon += "reader-tour.png";
       }
-      UITour.showInfo(win, browser.messageManager, target,
+      UITour.showInfo(win, target,
                       browserBundle.GetStringFromName("readingList.promo.firstUse.readerView.title"),
                       browserBundle.GetStringFromName("readingList.promo.firstUse.readerView.body"),
                       icon);
diff --git a/browser/themes/linux/browser.css b/browser/themes/linux/browser.css
index b50a82e13a8..2fc5de8757d 100644
--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -16,10 +16,11 @@
 
 %define forwardTransitionLength 150ms
 %define conditionalForwardWithUrlbar window:not([chromehidden~="toolbar"]) #urlbar-wrapper
-%define conditionalForwardWithUrlbarWidth 31
 
 :root {
   --backbutton-urlbar-overlap: 6px;
+  /* icon width + border + horizontal padding (includes the overlap from backbutton-urlbar-overlap) */
+  --forwardbutton-width: 31px;
 
   --toolbarbutton-hover-background: rgba(255,255,255,.5) linear-gradient(rgba(255,255,255,.5), transparent);
   --toolbarbutton-hover-bordercolor: rgba(0,0,0,.25);
@@ -743,7 +744,7 @@ menuitem:not([type]):not(.menuitem-tooltip):not(.menuitem-iconic-tooltip) {
   padding-right: 3px;
   border-left-style: none;
   border-radius: 0;
-  max-width: @conditionalForwardWithUrlbarWidth@px;
+  max-width: var(--forwardbutton-width);
 }
 
 @conditionalForwardWithUrlbar@:not([switchingtabs]) > #forward-button {
@@ -751,7 +752,7 @@ menuitem:not([type]):not(.menuitem-tooltip):not(.menuitem-iconic-tooltip) {
 }
 
 @conditionalForwardWithUrlbar@ > #forward-button[disabled] {
-  margin-left: -@conditionalForwardWithUrlbarWidth@px;
+  margin-left: calc(0px - var(--forwardbutton-width));
 }
 
 @conditionalForwardWithUrlbar@:hover:not([switchingtabs]) > #forward-button[disabled] {
@@ -761,7 +762,7 @@ menuitem:not([type]):not(.menuitem-tooltip):not(.menuitem-iconic-tooltip) {
 
 @conditionalForwardWithUrlbar@:not(:hover) > #forward-button[disabled] {
   /* when not hovered anymore, trigger a new transition to hide the forward button immediately */
-  margin-left: -@conditionalForwardWithUrlbarWidth@.01px;
+  margin-left: calc(-0.01px - var(--forwardbutton-width));
 }
 
 /* undo close tab menu item */
diff --git a/browser/themes/linux/devedition.css b/browser/themes/linux/devedition.css
index 66a5274c3fc..c0968466605 100644
--- a/browser/themes/linux/devedition.css
+++ b/browser/themes/linux/devedition.css
@@ -4,6 +4,10 @@
 
 %include ../shared/devedition.inc.css
 
+:root {
+  --forwardbutton-width: 29px;
+}
+
 :root[devtoolstheme="dark"] .findbar-closebutton:not(:hover),
 :root[devtoolstheme="dark"] #sidebar-header > .close-icon:not(:hover),
 .tab-close-button[visuallyselected]:not(:hover) {
diff --git a/browser/themes/osx/browser.css b/browser/themes/osx/browser.css
index 00cb4b59bbe..ff18a3ff4d1 100644
--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -8,7 +8,6 @@
 %filter substitution
 %define forwardTransitionLength 150ms
 %define conditionalForwardWithUrlbar window:not([chromehidden~="toolbar"]) #urlbar-wrapper
-%define conditionalForwardWithUrlbarWidth 32
 %define toolbarButtonPressed :hover:active:not([disabled="true"]):not([cui-areatype="menu-panel"])
 %define windowButtonMarginTop 11px
 
@@ -21,6 +20,8 @@
   --tabs-toolbar-color: #333;
 
   --backbutton-urlbar-overlap: 6px;
+  /* icon width + border + horizontal padding (includes the overlap from backbutton-urlbar-overlap) */
+  --forwardbutton-width: 32px;
 
   --toolbarbutton-hover-background: hsla(0,0%,100%,.1) linear-gradient(hsla(0,0%,100%,.3), hsla(0,0%,100%,.1)) padding-box;
   --toolbarbutton-hover-bordercolor: hsla(0,0%,0%,.2);
@@ -1371,7 +1372,7 @@ toolbar .toolbarbutton-1 > .toolbarbutton-menubutton-button {
 }
 
 @conditionalForwardWithUrlbar@ > #forward-button[disabled] {
-  margin-left: -@conditionalForwardWithUrlbarWidth@px;
+  margin-left: calc(0px - var(--forwardbutton-width));
 }
 
 @conditionalForwardWithUrlbar@:hover:not([switchingtabs]) > #forward-button[disabled] {
@@ -1381,7 +1382,7 @@ toolbar .toolbarbutton-1 > .toolbarbutton-menubutton-button {
 
 @conditionalForwardWithUrlbar@:not(:hover) > #forward-button[disabled] {
   /* when not hovered anymore, trigger a new transition to hide the forward button immediately */
-  margin-left: -@conditionalForwardWithUrlbarWidth@.01px;
+  margin-left: calc(-0.01px - var(--forwardbutton-width));
 }
 
 .unified-nav-back[_moz-menuactive]:-moz-locale-dir(ltr),
diff --git a/browser/themes/osx/devedition.css b/browser/themes/osx/devedition.css
index 467e24f9f1d..8e49e26bd10 100644
--- a/browser/themes/osx/devedition.css
+++ b/browser/themes/osx/devedition.css
@@ -41,6 +41,18 @@
 
 #forward-button {
   -moz-border-start: none !important;
+  /* browser.css and friends set up the width of the button to be 32px.
+   * They then set margin-left to -2px to ensure the button is not too wide
+   * compared to the back button, and set padding-left to center the icon
+   * correctly.
+   * In our theme, the back and forward buttons are the same width, with the
+   * back button being 32px with 1px border on both sides. To ensure the
+   * forward button's content box looks like it is the same size with width
+   * set to 32px and a 1px border on only 1 side, we overlap by 1px, so both
+   * buttons end up with a content box that looks like it's 30px.
+   */
+  margin-left: -1px;
+  padding-left: 1px;
 }
 
 #forward-button > .toolbarbutton-icon {
diff --git a/browser/themes/shared/incontentprefs/preferences.inc.css b/browser/themes/shared/incontentprefs/preferences.inc.css
index 16321bbf0f0..231a1bfc801 100644
--- a/browser/themes/shared/incontentprefs/preferences.inc.css
+++ b/browser/themes/shared/incontentprefs/preferences.inc.css
@@ -222,11 +222,12 @@ treecol {
 
 /* Privacy pane */
 
-#doNotTrackInfo,
+.doNotTrackLearnMore,
 #trackingProtectionPBMLearnMore,
 #trackingProtectionLearnMore {
   -moz-margin-start: 1.5em !important;
   margin-top: 0;
+  font-weight: normal;
 }
 
 /* Collapse the non-active vboxes in decks to use only the height the
diff --git a/browser/themes/windows/browser.css b/browser/themes/windows/browser.css
index eab731fac89..dba2201a129 100644
--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -20,6 +20,9 @@
 
   --backbutton-urlbar-overlap: 6px;
 
+  /* icon width + border + horizontal padding (includes the overlap from backbutton-urlbar-overlap) */
+  --forwardbutton-width: 31px;
+
   --toolbarbutton-vertical-inner-padding: 2px;
   --toolbarbutton-vertical-outer-padding: 8px;
 
@@ -939,9 +942,7 @@ toolbar[brighttext] .toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker {
   border-radius: 0 !important;
   padding-left: calc(var(--backbutton-urlbar-overlap) + 3px) !important;
   padding-right: 3px !important;
-% icon width + border + horizontal padding without --backbutton-urlbar-overlap
-%define forwardButtonWidth 25
-  max-width: calc(@forwardButtonWidth@px + var(--backbutton-urlbar-overlap)) !important;
+  max-width: var(--forwardbutton-width) !important;
 }
 
 @conditionalForwardWithUrlbar@:not([switchingtabs]) > #forward-button {
@@ -949,7 +950,7 @@ toolbar[brighttext] .toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker {
 }
 
 @conditionalForwardWithUrlbar@ > #forward-button[disabled] {
-  margin-left: calc(-@forwardButtonWidth@px - var(--backbutton-urlbar-overlap));
+  margin-left: calc(0px - var(--forwardbutton-width));
 }
 
 @conditionalForwardWithUrlbar@:hover:not([switchingtabs]) > #forward-button[disabled] {
@@ -959,7 +960,7 @@ toolbar[brighttext] .toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker {
 
 @conditionalForwardWithUrlbar@:not(:hover) > #forward-button[disabled] {
   /* when not hovered anymore, trigger a new transition to hide the forward button immediately */
-  margin-left: calc(-@forwardButtonWidth@.01px - var(--backbutton-urlbar-overlap));
+  margin-left: calc(-0.01px - var(--forwardbutton-width));
 }
 
 #back-button {
diff --git a/browser/themes/windows/devedition.css b/browser/themes/windows/devedition.css
index f441bf95e8a..6c9616e8228 100644
--- a/browser/themes/windows/devedition.css
+++ b/browser/themes/windows/devedition.css
@@ -4,6 +4,10 @@
 
 %include ../shared/devedition.inc.css
 
+:root {
+  --forwardbutton-width: 29px;
+}
+
 :root[devtoolstheme="dark"],
 :root[devtoolstheme="light"] {
    /* Matches the #browser-border-start, #browser-border-end color */
diff --git a/configure.in b/configure.in
index c1acb483a11..ebf2d504b69 100644
--- a/configure.in
+++ b/configure.in
@@ -5725,6 +5725,7 @@ MOZ_DIRECTX_SDK_PATH=
 MOZ_D3DCOMPILER_XP_DLL=
 MOZ_D3DCOMPILER_XP_CAB=
 
+if test "$COMPILE_ENVIRONMENT" ; then
 case "$target_os" in
 *mingw*)
     MOZ_ANGLE_RENDERER=1
@@ -5887,7 +5888,9 @@ if test -n "$MOZ_ANGLE_RENDERER"; then
       AC_MSG_ERROR([  Install Windows SDK 8.0+, as well as DirectX SDK (June 2010 version or newer), or reconfigure without this flag.])
     fi
   fi
-fi
+fi # MOZ_ANGLE_RENDERER
+
+fi # COMPILE_ENVIRONMENT
 
 
 dnl ========================================================
@@ -6280,41 +6283,49 @@ dnl minimum minor version of Unicode NSIS isn't in the path
 dnl (unless in case of cross compiling, for which Unicode
 dnl is not yet sufficient).
 if test "$OS_ARCH" = "WINNT"; then
-    MIN_NSIS_MAJOR_VER=2
-    MIN_NSIS_MINOR_VER=46
-    MOZ_PATH_PROGS(MAKENSISU, $MAKENSISU makensis-3.0b1.exe makensisu-3.0a2.exe makensisu-2.46.exe makensis)
+    MIN_NSIS_MAJOR_VER=3
+    MIN_NSIS_MINOR_VER=0
+    MIN_NSIS_PRERELEASE_TYPE=b
+    MIN_NSIS_PRERELEASE_VER=1
+    MOZ_PATH_PROGS(MAKENSISU, $MAKENSISU makensis-3.0b3.exe makensis-3.0b1.exe makensis)
     if test -n "$MAKENSISU" -a "$MAKENSISU" != ":"; then
       AC_MSG_RESULT([yes])
       MAKENSISU_VER=`"$MAKENSISU" -version 2>/dev/null`
       changequote(,)
-      MAKENSISU_PARSED_VER=`echo "$MAKENSISU_VER" | sed -e '/-Unicode/!s/.*//g' -e 's/^v\([0-9]\+\.[0-9]\+\).*\-Unicode$/\1/g'`
+      MAKENSISU_PARSED_VER=`echo "$MAKENSISU_VER" | sed -e 's/^v\([0-9]\+\.[0-9]\+\).*$/\1/g'`
       changequote([,])
-      if test "$MAKENSISU_PARSED_VER" = ""; then
-          changequote(,)
-          MAKENSISU_PARSED_VER=`echo "$MAKENSISU_VER" | sed -e 's/^v\([0-9]\+\.[0-9]\+\).*$/\1/g'`
-          changequote([,])
-      fi
       MAKENSISU_MAJOR_VER=0
       MAKENSISU_MINOR_VER=0
+      MAKENSISU_PRERELEASE_TYPE=$MIN_NSIS_PRERELEASE_TYPE
+      MAKENSISU_PRERELEASE_VER=$MIN_NSIS_PRERELEASE_VER
       if test ! "$MAKENSISU_PARSED_VER" = ""; then
           MAKENSISU_MAJOR_VER=`echo $MAKENSISU_PARSED_VER | $AWK -F\. '{ print $1 }'`
           MAKENSISU_MINOR_VER=`echo $MAKENSISU_PARSED_VER | $AWK -F\. '{ print $2 }'`
+          changequote(,)
+          MAKENSISU_PARSED_PRERELEASE=`echo "$MAKENSISU_VER" | sed -e 's/^v[0-9]\+\.[0-9]\+\([^0-9]\+\)\([0-9]\+\).*$/\1.\2/g'`
+          changequote([,])
+          if test ! "$MAKENSISU_PARSED_PRERELEASE" = "$MAKENSISU_VER"; then
+              MAKENSISU_PRERELEASE_TYPE=`echo $MAKENSISU_PARSED_PRERELEASE | $AWK -F\. '{ print $1 }'`
+              MAKENSISU_PRERELEASE_VER=`echo $MAKENSISU_PARSED_PRERELEASE | $AWK -F\. '{ print $2 }'`
+          fi
       fi
-      AC_MSG_CHECKING([for Unicode NSIS version $MIN_NSIS_MAJOR_VER.$MIN_NSIS_MINOR_VER or greater])
+      AC_MSG_CHECKING([for NSIS version $MIN_NSIS_MAJOR_VER.$MIN_NSIS_MINOR_VER$MIN_NSIS_PRERELEASE_TYPE$MIN_NSIS_PRERELEASE_VER or greater])
       if test "$MAKENSISU_MAJOR_VER" -eq $MIN_NSIS_MAJOR_VER -a \
-              "$MAKENSISU_MINOR_VER" -ge $MIN_NSIS_MINOR_VER ||
-         test "$MAKENSISU_MAJOR_VER" -gt $MIN_NSIS_MAJOR_VER; then
+              "$MAKENSISU_MINOR_VER" -ge $MIN_NSIS_MINOR_VER -a \
+              "$MAKENSISU_PRERELEASE_TYPE" = "$MIN_NSIS_PRERELEASE_TYPE" -a \
+              "$MAKENSISU_PRERELEASE_VER" -ge $MIN_NSIS_PRERELEASE_VER; then
           AC_MSG_RESULT([yes])
+          AC_MSG_RESULT([Found NSIS Version: $MAKENSISU_VER])
       else
           AC_MSG_RESULT([no])
           if test -z "$CROSS_COMPILE"; then
-            AC_MSG_ERROR([To build the installer you must have the latest MozillaBuild or Unicode NSIS version $MIN_NSIS_MAJOR_VER.$MIN_NSIS_MINOR_VER or greater in your path.])
+            AC_MSG_ERROR([To build the installer you must have the latest MozillaBuild or NSIS version $MIN_NSIS_MAJOR_VER.$MIN_NSIS_MINOR_VER$MIN_NSIS_PRERELEASE_TYPE$MIN_NSIS_PRERELEASE_VER or greater in your path.])
           else
             MAKENSISU=
           fi
       fi
     elif test -z "$CROSS_COMPILE"; then
-      AC_MSG_ERROR([To build the installer you must have the latest MozillaBuild or Unicode NSIS version $MIN_NSIS_MAJOR_VER.$MIN_NSIS_MINOR_VER or greater in your path.])
+      AC_MSG_ERROR([To build the installer you must have the latest MozillaBuild or NSIS version $MIN_NSIS_MAJOR_VER.$MIN_NSIS_MINOR_VER$MIN_NSIS_PRERELEASE_TYPE$MIN_NSIS_PRERELEASE_VER or greater in your path.])
     else
       MAKENSISU=
     fi
@@ -8146,11 +8157,14 @@ if test "$MOZ_TREE_CAIRO"; then
         MOZ_ENABLE_D2D_SURFACE=1
         MOZ_ENABLE_DWRITE_FONT=1
 
-        MOZ_CHECK_HEADER(d3d9.h, MOZ_ENABLE_D3D9_LAYER=1)
+        if test "$COMPILE_ENVIRONMENT"; then
 
-        dnl D3D10 Layers depend on D2D Surfaces.
-        if test -n "$WIN32_D2D_SURFACE_FEATURE"; then
-          MOZ_CHECK_HEADER(d3d10.h, MOZ_ENABLE_D3D10_LAYER=1)
+          MOZ_CHECK_HEADER(d3d9.h, MOZ_ENABLE_D3D9_LAYER=1)
+
+          dnl D3D10 Layers depend on D2D Surfaces.
+          if test -n "$WIN32_D2D_SURFACE_FEATURE"; then
+            MOZ_CHECK_HEADER(d3d10.h, MOZ_ENABLE_D3D10_LAYER=1)
+          fi
         fi
         ;;
     esac
diff --git a/devtools/chrome.manifest b/devtools/chrome.manifest
index bcf3431992d..c0c1a163cdb 100644
--- a/devtools/chrome.manifest
+++ b/devtools/chrome.manifest
@@ -1,6 +1,7 @@
 content devtools client/
 skin devtools classic/1.0 client/themes/
 resource devtools .
+locale devtools en-US client/locales/en-US/
 
 content webide client/webide/content/
 skin webide classic/1.0 client/webide/themes/
diff --git a/devtools/server/tests/unit/test_setBreakpoint-on-line-with-no-offets-in-gcd-script.js b/devtools/server/tests/unit/test_setBreakpoint-on-line-with-no-offets-in-gcd-script.js
deleted file mode 100644
index 27eb90c3cb2..00000000000
--- a/devtools/server/tests/unit/test_setBreakpoint-on-line-with-no-offets-in-gcd-script.js
+++ /dev/null
@@ -1,54 +0,0 @@
-"use strict";
-
-var SOURCE_URL = getFileUrl("setBreakpoint-on-line-with-no-offests-in-gcd-script.js");
-
-function run_test() {
-  return Task.spawn(function* () {
-    do_test_pending();
-
-    let global = testGlobal("test");
-    loadSubScript(SOURCE_URL, global);
-    Cu.forceGC();
-
-    DebuggerServer.registerModule("xpcshell-test/testactors");
-    DebuggerServer.init(() => true);
-    DebuggerServer.addTestGlobal(global);
-    let client = new DebuggerClient(DebuggerServer.connectPipe());
-    yield connect(client);
-
-    let tab = yield findTab(client, "test");
-    let [, tabClient] = yield attachTab(client, tab);
-    let [, threadClient] = yield attachThread(tabClient);
-    yield resume(threadClient);
-
-    let source = yield findSource(threadClient, SOURCE_URL);
-    let sourceClient = threadClient.source(source);
-
-    let location = { line: 7 };
-    let [packet, breakpointClient] = yield setBreakpoint(sourceClient, location);
-    do_check_true(packet.isPending);
-
-    executeSoon(function () {
-      reload(tabClient).then(function () {
-        loadSubScript(SOURCE_URL, global);
-      });
-    });
-    packet = yield waitForPaused(threadClient);
-    do_check_eq(packet.type, "paused");
-    let why = packet.why;
-    do_check_eq(why.type, "breakpoint");
-    do_check_eq(why.actors.length, 1);
-    do_check_eq(why.actors[0], breakpointClient.actor);
-    let frame = packet.frame;
-    let where = frame.where;
-    do_check_eq(where.source.actor, source.actor);
-    do_check_eq(where.line, location.line + 1);
-    let variables = frame.environment.bindings.variables;
-    do_check_eq(variables.a.value, 1);
-    do_check_eq(variables.c.value.type, "undefined");
-    yield resume(threadClient);
-
-    yield close(client);
-    do_test_finished();
-  });
-}
diff --git a/mobile/android/app/mobile.js b/mobile/android/app/mobile.js
index 912a3c8d2c5..c37840c5641 100644
--- a/mobile/android/app/mobile.js
+++ b/mobile/android/app/mobile.js
@@ -471,8 +471,13 @@ pref("plugin.default.state", 1);
 // The breakpad report server to link to in about:crashes
 pref("breakpad.reportURL", "https://crash-stats.mozilla.com/report/index/");
 pref("app.support.baseURL", "http://support.mozilla.org/1/mobile/%VERSION%/%OS%/%LOCALE%/");
+
 // Used to submit data to input from about:feedback
 pref("app.feedback.postURL", "https://input.mozilla.org/api/v1/feedback/");
+
+// URL for feedback page
+pref("app.feedbackURL", "about:feedback");
+
 pref("app.privacyURL", "https://www.mozilla.org/privacy/firefox/");
 pref("app.creditsURL", "http://www.mozilla.org/credits/");
 pref("app.channelURL", "http://www.mozilla.org/%LOCALE%/firefox/channel/");
diff --git a/mobile/android/base/java/org/mozilla/gecko/SessionParser.java b/mobile/android/base/java/org/mozilla/gecko/SessionParser.java
index 0f2649b4e5b..aab81073d5c 100644
--- a/mobile/android/base/java/org/mozilla/gecko/SessionParser.java
+++ b/mobile/android/base/java/org/mozilla/gecko/SessionParser.java
@@ -67,7 +67,14 @@ public abstract class SessionParser {
         int selectedIndex = -1;
         try {
             for (String sessionString : sessionStrings) {
-                final JSONObject window = new JSONObject(sessionString).getJSONArray("windows").getJSONObject(0);
+                final JSONArray windowsArray = new JSONObject(sessionString).getJSONArray("windows");
+                if (windowsArray.length() == 0) {
+                    // Session json can be empty if the user has opted out of session restore.
+                    Log.d(LOGTAG, "Session restore file is empty, no session entries found.");
+                    continue;
+                }
+
+                final JSONObject window = windowsArray.getJSONObject(0);
                 final JSONArray tabs = window.getJSONArray("tabs");
                 final int optSelected = window.optInt("selected", -1);
                 final JSONArray closedTabs = window.optJSONArray("closedTabs");
diff --git a/mobile/android/base/java/org/mozilla/gecko/preferences/GeckoPreferences.java b/mobile/android/base/java/org/mozilla/gecko/preferences/GeckoPreferences.java
index 6d28c998669..3a047180e3e 100644
--- a/mobile/android/base/java/org/mozilla/gecko/preferences/GeckoPreferences.java
+++ b/mobile/android/base/java/org/mozilla/gecko/preferences/GeckoPreferences.java
@@ -133,18 +133,15 @@ OnSharedPreferenceChangeListener
     private static final String PREFS_TRACKING_PROTECTION_PB = "privacy.trackingprotection.pbmode.enabled";
     public static final String PREFS_VOICE_INPUT_ENABLED = NON_PREF_PREFIX + "voice_input_enabled";
     public static final String PREFS_QRCODE_ENABLED = NON_PREF_PREFIX + "qrcode_enabled";
-    private static final String PREFS_ADVANCED = NON_PREF_PREFIX + "advanced.enabled";
-    private static final String PREFS_ACCESSIBILITY = NON_PREF_PREFIX + "accessibility.enabled";
-    private static final String PREFS_CUSTOMIZE_HOME = NON_PREF_PREFIX + "customize_home";
     private static final String PREFS_TRACKING_PROTECTION_PRIVATE_BROWSING = "privacy.trackingprotection.pbmode.enabled";
     private static final String PREFS_TRACKING_PROTECTION_LEARN_MORE = NON_PREF_PREFIX + "trackingprotection.learn_more";
     private static final String PREFS_CLEAR_PRIVATE_DATA = NON_PREF_PREFIX + "privacy.clear";
     private static final String PREFS_CLEAR_PRIVATE_DATA_EXIT = NON_PREF_PREFIX + "history.clear_on_exit";
     private static final String PREFS_SCREEN_ADVANCED = NON_PREF_PREFIX + "advanced_screen";
-    private static final String PREFS_CATEGORY_HOMEPAGE = NON_PREF_PREFIX + "category_homepage";
     public static final String PREFS_HOMEPAGE = NON_PREF_PREFIX + "homepage";
     public static final String PREFS_HISTORY_SAVED_SEARCH = NON_PREF_PREFIX + "search.search_history.enabled";
     private static final String PREFS_FAQ_LINK = NON_PREF_PREFIX + "faq.link";
+    private static final String PREFS_FEEDBACK_LINK = NON_PREF_PREFIX + "feedback.link";
 
     private static final String ACTION_STUMBLER_UPLOAD_PREF = AppConstants.ANDROID_PACKAGE_NAME + ".STUMBLER_PREF";
 
@@ -852,6 +849,18 @@ OnSharedPreferenceChangeListener
 
                     final String url = getResources().getString(R.string.faq_link, VERSION, OS, LOCALE);
                     ((LinkPreference) pref).setUrl(url);
+                } else if (PREFS_FEEDBACK_LINK.equals(key)) {
+                    PrefsHelper.getPref("app.feedbackURL", new PrefsHelper.PrefHandlerBase() {
+                        @Override
+                        public void prefValue(String prefName, final String value) {
+                            ThreadUtils.postToUiThread(new Runnable() {
+                                @Override
+                                public void run() {
+                                    ((LinkPreference) pref).setUrl(value);
+                                }
+                            });
+                        }
+                    });
                 }
 
                 // Some Preference UI elements are not actually preferences,
diff --git a/mobile/android/base/java/org/mozilla/gecko/restrictions/RestrictedProfileConfiguration.java b/mobile/android/base/java/org/mozilla/gecko/restrictions/RestrictedProfileConfiguration.java
index 887fe6fa450..e47bcf60102 100644
--- a/mobile/android/base/java/org/mozilla/gecko/restrictions/RestrictedProfileConfiguration.java
+++ b/mobile/android/base/java/org/mozilla/gecko/restrictions/RestrictedProfileConfiguration.java
@@ -35,12 +35,7 @@ public class RestrictedProfileConfiguration implements RestrictionConfiguration
         configuration.put(Restrictable.ADVANCED_SETTINGS, false);
         configuration.put(Restrictable.CAMERA_MICROPHONE, false);
         configuration.put(Restrictable.DATA_CHOICES, false);
-
-        // Hold behind Nightly flag until we have an actual block list deployed.
-        if (AppConstants.NIGHTLY_BUILD) {
-            configuration.put(Restrictable.BLOCK_LIST, false);
-        }
-
+        configuration.put(Restrictable.BLOCK_LIST, false);
         configuration.put(Restrictable.TELEMETRY, false);
         configuration.put(Restrictable.HEALTH_REPORT, true);
         configuration.put(Restrictable.DEFAULT_THEME, true);
@@ -49,12 +44,18 @@ public class RestrictedProfileConfiguration implements RestrictionConfiguration
     /**
      * These restrictions are hidden from the admin configuration UI.
      */
-    private static List<Restrictable> hiddenRestrictions = Arrays.asList(
-            Restrictable.MASTER_PASSWORD,
-            Restrictable.GUEST_BROWSING,
-            Restrictable.DATA_CHOICES,
-            Restrictable.DEFAULT_THEME
-    );
+    private static List<Restrictable> hiddenRestrictions = new ArrayList<>();
+    static {
+        hiddenRestrictions.add(Restrictable.MASTER_PASSWORD);
+        hiddenRestrictions.add(Restrictable.GUEST_BROWSING);
+        hiddenRestrictions.add(Restrictable.DATA_CHOICES);
+        hiddenRestrictions.add(Restrictable.DEFAULT_THEME);
+
+        // Hold behind Nightly flag until we have an actual block list deployed.
+        if (!AppConstants.NIGHTLY_BUILD){
+            hiddenRestrictions.add(Restrictable.BLOCK_LIST);
+        }
+    }
 
     /* package-private */ static boolean shouldHide(Restrictable restrictable) {
         return hiddenRestrictions.contains(restrictable);
diff --git a/mobile/android/base/java/org/mozilla/gecko/widget/DateTimePicker.java b/mobile/android/base/java/org/mozilla/gecko/widget/DateTimePicker.java
index 5c464b944cf..5db1f5d817c 100644
--- a/mobile/android/base/java/org/mozilla/gecko/widget/DateTimePicker.java
+++ b/mobile/android/base/java/org/mozilla/gecko/widget/DateTimePicker.java
@@ -354,7 +354,7 @@ public class DateTimePicker extends FrameLayout {
         mDaySpinnerInput = (EditText) mDaySpinner.getChildAt(1);
 
         mMonthSpinner = setupSpinner(R.id.month, 1,
-                                     mTempDate.get(Calendar.MONTH));
+                                     mTempDate.get(Calendar.MONTH) + 1); // Month is 0-based
         mMonthSpinner.setFormatter(TWO_DIGIT_FORMATTER);
         mMonthSpinner.setDisplayedValues(mShortMonths);
         mMonthSpinnerInput = (EditText) mMonthSpinner.getChildAt(1);
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_amazon.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_amazon.png
new file mode 100644
index 00000000000..776cc4934c8
Binary files /dev/null and b/mobile/android/base/resources/drawable-hdpi/suggestedsites_amazon.png differ
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_facebook.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_facebook.png
new file mode 100644
index 00000000000..340b9a5e4d2
Binary files /dev/null and b/mobile/android/base/resources/drawable-hdpi/suggestedsites_facebook.png differ
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxaddons.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxaddons.png
deleted file mode 100644
index 4afab91bd2c..00000000000
Binary files a/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxaddons.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxmarketplace.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxmarketplace.png
deleted file mode 100644
index 1cb39f7efa4..00000000000
Binary files a/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxmarketplace.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxsupport.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxsupport.png
deleted file mode 100644
index 40295739df4..00000000000
Binary files a/mobile/android/base/resources/drawable-hdpi/suggestedsites_fxsupport.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_mozilla.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_mozilla.png
deleted file mode 100644
index 615e55d53fb..00000000000
Binary files a/mobile/android/base/resources/drawable-hdpi/suggestedsites_mozilla.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_twitter.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_twitter.png
new file mode 100644
index 00000000000..f3d9fd2380e
Binary files /dev/null and b/mobile/android/base/resources/drawable-hdpi/suggestedsites_twitter.png differ
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_wikipedia.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_wikipedia.png
new file mode 100644
index 00000000000..9c6efc14ad0
Binary files /dev/null and b/mobile/android/base/resources/drawable-hdpi/suggestedsites_wikipedia.png differ
diff --git a/mobile/android/base/resources/drawable-hdpi/suggestedsites_youtube.png b/mobile/android/base/resources/drawable-hdpi/suggestedsites_youtube.png
new file mode 100644
index 00000000000..7e73e607503
Binary files /dev/null and b/mobile/android/base/resources/drawable-hdpi/suggestedsites_youtube.png differ
diff --git a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_amazon.png b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_amazon.png
new file mode 100644
index 00000000000..012060dd9a5
Binary files /dev/null and b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_amazon.png differ
diff --git a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_facebook.png b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_facebook.png
new file mode 100644
index 00000000000..b97f9cba90b
Binary files /dev/null and b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_facebook.png differ
diff --git a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_fxaddons.png b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_fxaddons.png
deleted file mode 100644
index 43b04b52944..00000000000
Binary files a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_fxaddons.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_fxsupport.png b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_fxsupport.png
deleted file mode 100644
index 25338e447d4..00000000000
Binary files a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_fxsupport.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_mozilla.png b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_mozilla.png
deleted file mode 100644
index 03a2e9491c1..00000000000
Binary files a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_mozilla.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_twitter.png b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_twitter.png
new file mode 100644
index 00000000000..75bc311c072
Binary files /dev/null and b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_twitter.png differ
diff --git a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_wikipedia.png b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_wikipedia.png
new file mode 100644
index 00000000000..76140d48b2a
Binary files /dev/null and b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_wikipedia.png differ
diff --git a/mobile/android/base/resources/drawable-xhdpi/suggestedsites_youtube.png b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_youtube.png
new file mode 100644
index 00000000000..2896a9c17a9
Binary files /dev/null and b/mobile/android/base/resources/drawable-xhdpi/suggestedsites_youtube.png differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_amazon.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_amazon.png
new file mode 100644
index 00000000000..5b0d2fdc5f7
Binary files /dev/null and b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_amazon.png differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_facebook.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_facebook.png
new file mode 100644
index 00000000000..46e2db58822
Binary files /dev/null and b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_facebook.png differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxaddons.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxaddons.png
deleted file mode 100644
index e0a3b26c87a..00000000000
Binary files a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxaddons.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxmarketplace.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxmarketplace.png
deleted file mode 100644
index 4a69a3ec07c..00000000000
Binary files a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxmarketplace.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxsupport.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxsupport.png
deleted file mode 100644
index b0c336d910c..00000000000
Binary files a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_fxsupport.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_mozilla.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_mozilla.png
deleted file mode 100644
index 0b35eb7b13a..00000000000
Binary files a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_mozilla.png and /dev/null differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_twitter.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_twitter.png
new file mode 100644
index 00000000000..781b7b5a11f
Binary files /dev/null and b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_twitter.png differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_wikipedia.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_wikipedia.png
new file mode 100644
index 00000000000..a324694e91a
Binary files /dev/null and b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_wikipedia.png differ
diff --git a/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_youtube.png b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_youtube.png
new file mode 100644
index 00000000000..d201b622105
Binary files /dev/null and b/mobile/android/base/resources/drawable-xxhdpi/suggestedsites_youtube.png differ
diff --git a/mobile/android/base/resources/xml/preferences_vendor.xml b/mobile/android/base/resources/xml/preferences_vendor.xml
index e44cc4e98cc..38eba9d303c 100644
--- a/mobile/android/base/resources/xml/preferences_vendor.xml
+++ b/mobile/android/base/resources/xml/preferences_vendor.xml
@@ -19,7 +19,6 @@
 
     <org.mozilla.gecko.preferences.LinkPreference android:key="android.not_a_preference.feedback.link"
                                                   android:title="@string/pref_vendor_feedback"
-                                                  android:persistent="false"
-                                                  url="about:feedback" />
+                                                  android:persistent="false"/>
 
 </PreferenceScreen>
diff --git a/mobile/android/chrome/content/Feedback.js b/mobile/android/chrome/content/Feedback.js
index 03ed8ee82ce..465e8f46bd3 100644
--- a/mobile/android/chrome/content/Feedback.js
+++ b/mobile/android/chrome/content/Feedback.js
@@ -4,15 +4,57 @@
 "use strict";
 
 var Feedback = {
-  observe: function(aMessage, aTopic, aData) {
-    if (aTopic !== "Feedback:Show")
-      return;
 
-    // Only prompt for feedback if this isn't a distribution build.
+  get _feedbackURL() {
+    delete this._feedbackURL;
+    return this._feedbackURL = Services.prefs.getCharPref("app.feedbackURL");
+  },
+
+  observe: function(aMessage, aTopic, aData) {
+    if (aTopic !== "Feedback:Show") {
+      return;
+    }
+
+    // Don't prompt for feedback in distribution builds.
     try {
       Services.prefs.getCharPref("distribution.id");
-    } catch (e) {
-      BrowserApp.addTab("about:feedback?source=feedback-prompt", { selected: true, parentId: BrowserApp.selectedTab.id });
+      return;
+    } catch (e) {}
+
+    let url = this._feedbackURL + "?source=feedback-prompt";
+    let browser = BrowserApp.selectOrAddTab(url, { parentId: BrowserApp.selectedTab.id }).browser;
+    browser.addEventListener("FeedbackClose", this, false, true);
+    browser.addEventListener("FeedbackMaybeLater", this, false, true);
+    browser.addEventListener("FeedbackOpenPlay", this, false, true);
+  },
+
+  handleEvent: function(event) {
+    if (!this._isAllowed(event.target)) {
+      return;
     }
+
+    switch (event.type) {
+      case "FeedbackClose":
+        // Do nothing.
+        break;
+
+      case "FeedbackMaybeLater":
+        Messaging.sendRequest({ type: "Feedback:MaybeLater" });
+        break;
+
+      case "FeedbackOpenPlay":
+        Messaging.sendRequest({ type: "Feedback:OpenPlayStore" });
+        break;
+
+    }
+
+    let win = event.target.ownerDocument.defaultView.top;
+    BrowserApp.closeTab(BrowserApp.getTabForWindow(win));
+  },
+
+  _isAllowed: function(node) {
+    let uri = node.ownerDocument.documentURIObject;
+    let feedbackURI = Services.io.newURI(this._feedbackURL, null, null);
+    return uri.prePath === feedbackURI.prePath;
   }
 };
diff --git a/mobile/locales/en-US/chrome/region.properties b/mobile/locales/en-US/chrome/region.properties
index 35bdf22712c..6d89a6f0fe7 100644
--- a/mobile/locales/en-US/chrome/region.properties
+++ b/mobile/locales/en-US/chrome/region.properties
@@ -51,24 +51,31 @@ browser.contentHandlers.types.0.uri=https://add.my.yahoo.com/rss?url=%s
 # mobile/android/tests/browser/robocop/testDistribution.java
 # to reflect the new set of IDs reported as tiles data.
 #
-browser.suggestedsites.list.0=mozilla
-browser.suggestedsites.list.1=fxaddons
-browser.suggestedsites.list.2=fxsupport
+browser.suggestedsites.list.0=facebook
+browser.suggestedsites.list.1=youtube
+browser.suggestedsites.list.2=amazon
+browser.suggestedsites.list.3=wikipedia
+browser.suggestedsites.list.4=twitter
 
-browser.suggestedsites.mozilla.title=The Mozilla Project
-browser.suggestedsites.mozilla.url=https://www.mozilla.org/en-US/
-browser.suggestedsites.mozilla.bgcolor=#ce4e41
-browser.suggestedsites.mozilla.trackingid=632
+browser.suggestedsites.facebook.title=Facebook
+browser.suggestedsites.facebook.url=https://m.facebook.com/
+browser.suggestedsites.facebook.bgcolor=#385185
 
-browser.suggestedsites.fxaddons.title=Add-ons: Customize Firefox
-browser.suggestedsites.fxaddons.url=https://addons.mozilla.org/en-US/android/
-browser.suggestedsites.fxaddons.bgcolor=#62be06
-browser.suggestedsites.fxaddons.trackingid=630
+browser.suggestedsites.youtube.title=YouTube
+browser.suggestedsites.youtube.url=https://m.youtube.com/
+browser.suggestedsites.youtube.bgcolor=#cd201f
 
-browser.suggestedsites.fxsupport.title=Firefox Help and Support
-browser.suggestedsites.fxsupport.url=https://support.mozilla.org/en-US/products/mobile
-browser.suggestedsites.fxsupport.bgcolor=#f37c00
-browser.suggestedsites.fxsupport.trackingid=631
+browser.suggestedsites.amazon.title=Amazon
+browser.suggestedsites.amazon.url=https://www.amazon.com/
+browser.suggestedsites.amazon.bgcolor=#000000
+
+browser.suggestedsites.wikipedia.title=Wikipedia
+browser.suggestedsites.wikipedia.url=https://www.wikipedia.org/
+browser.suggestedsites.wikipedia.bgcolor=#000000
+
+browser.suggestedsites.twitter.title=Twitter
+browser.suggestedsites.twitter.url=https://mobile.twitter.com/
+browser.suggestedsites.twitter.bgcolor=#55acee
 
 browser.suggestedsites.restricted.list.0=restricted_fxsupport
 browser.suggestedsites.restricted.list.1=webmaker
diff --git a/netwerk/base/nsIBrowserSearchService.idl b/netwerk/base/nsIBrowserSearchService.idl
index b8273dc4784..f0716d6e664 100644
--- a/netwerk/base/nsIBrowserSearchService.idl
+++ b/netwerk/base/nsIBrowserSearchService.idl
@@ -420,14 +420,17 @@ interface nsIBrowserSearchService : nsISupports
   void removeEngine(in nsISearchEngine engine);
 
   /**
-   * The default search engine. Returns the first visible engine if the default
-   * engine is hidden. May be null if there are no visible search engines.
+   * Alias for the currentEngine attribute, kept for add-on compatibility.
    */
   attribute nsISearchEngine defaultEngine;
 
   /**
-   * The currently active search engine. May be null if there are no visible
-   * search engines.
+   * The currently active search engine.
+   * Unless the application doesn't ship any search plugin, this should never
+   * be null. If the currently active engine is removed, this attribute will
+   * fallback first to the original default engine if it's not hidden, then to
+   * the first visible engine, and as a last resort it will unhide the original
+   * default engine.
    */
   attribute nsISearchEngine currentEngine;
 
diff --git a/python/mach/mach/mixin/process.py b/python/mach/mach/mixin/process.py
index 5b06da3b60e..79a0cbbb811 100644
--- a/python/mach/mach/mixin/process.py
+++ b/python/mach/mach/mixin/process.py
@@ -75,7 +75,7 @@ class ProcessExecutionMixin(LoggingMixin):
         """
         args = self._normalize_command(args, require_unix_environment)
 
-        self.log(logging.INFO, 'new_process', {'args': args}, ' '.join(args))
+        self.log(logging.INFO, 'new_process', {'args': ' '.join(args)}, '{args}')
 
         def handleLine(line):
             # Converts str to unicode on Python 2 and bytes to str on Python 3.
@@ -144,7 +144,7 @@ class ProcessExecutionMixin(LoggingMixin):
             ensure_exit_code = 0
 
         if status != ensure_exit_code:
-            raise Exception('Process executed with non-0 exit code: %s' % args)
+            raise Exception('Process executed with non-0 exit code %d: %s' % (status, args))
 
         return status
 
diff --git a/python/mozbuild/mozbuild/artifacts.py b/python/mozbuild/mozbuild/artifacts.py
index cd427617e23..6b599bd051d 100644
--- a/python/mozbuild/mozbuild/artifacts.py
+++ b/python/mozbuild/mozbuild/artifacts.py
@@ -50,6 +50,7 @@ import re
 import shutil
 import stat
 import subprocess
+import tarfile
 import tempfile
 import urlparse
 import zipfile
@@ -131,6 +132,41 @@ class AndroidArtifactJob(ArtifactJob):
                 writer.add(basename.encode('utf-8'), f)
 
 
+class LinuxArtifactJob(ArtifactJob):
+    def process_artifact(self, filename, processed_filename):
+        with JarWriter(file=processed_filename, optimize=False, compress_level=5) as writer:
+            prefix = 'firefox/'
+            whitelist = {
+                'application.ini',
+                'crashreporter',
+                'dependentlibs.list',
+                'firefox',
+                'firefox-bin',
+                'platform.ini',
+                'plugin-container',
+                'updater',
+                'webapprt-stub',
+            }
+            with tarfile.open(filename) as reader:
+                for f in reader:
+                    if not f.isfile():
+                        continue
+
+                    if not f.name.startswith(prefix):
+                        raise ValueError('Archive format changed! Filename should start with "firefox/"; was "{filename}"'.format(filename=f.name))
+                    basename = f.name[len(prefix):]
+
+                    if not basename.endswith('.so') and \
+                       basename not in whitelist:
+                        continue
+
+                    self.log(logging.INFO, 'artifact',
+                        {'basename': basename},
+                        'Adding {basename} to processed archive')
+
+                    writer.add(basename.encode('utf-8'), reader.extractfile(f), mode=f.mode)
+
+
 class MacArtifactJob(ArtifactJob):
     def process_artifact(self, filename, processed_filename):
         tempdir = tempfile.mkdtemp()
@@ -223,14 +259,44 @@ class MacArtifactJob(ArtifactJob):
                 pass
 
 
-# Keep the keys of this map in sync with the |mach artifact| --job options.
+class WinArtifactJob(ArtifactJob):
+    def process_artifact(self, filename, processed_filename):
+        with JarWriter(file=processed_filename, optimize=False, compress_level=5) as writer:
+            prefix = 'firefox/'
+            whitelist = {
+                'dependentlibs.list',
+                'platform.ini',
+                'application.ini',
+            }
+            for f in JarReader(filename):
+                if not f.filename.startswith(prefix):
+                    raise ValueError('Archive format changed! Filename should start with "firefox/"; was "{filename}"'.format(filename=f.filename))
+                basename = f.filename[len(prefix):]
+
+                if not basename.endswith('.dll') and \
+                   not basename.endswith('.exe') and \
+                   basename not in whitelist:
+                    continue
+
+                self.log(logging.INFO, 'artifact',
+                    {'basename': basename},
+                    'Adding {basename} to processed archive')
+
+                writer.add(basename.encode('utf-8'), f)
+
+
+# Keep the keys of this map in sync with the |mach artifact| --job
+# options.  The keys of this map correspond to entries at
+# https://tools.taskcluster.net/index/artifacts/#buildbot.branches.mozilla-central/buildbot.branches.mozilla-central.
 JOB_DETAILS = {
     # 'android-api-9': (AndroidArtifactJob, 'public/build/fennec-(.*)\.android-arm\.apk'),
     'android-api-11': (AndroidArtifactJob, 'public/build/fennec-(.*)\.android-arm\.apk'),
     'android-x86': (AndroidArtifactJob, 'public/build/fennec-(.*)\.android-i386\.apk'),
-    # 'linux': (ArtifactJob, 'public/build/firefox-(.*)\.linux-i686\.tar\.bz2'),
-    # 'linux64': (ArtifactJob, 'public/build/firefox-(.*)\.linux-x86_64\.tar\.bz2'),
+    'linux': (LinuxArtifactJob, 'public/build/firefox-(.*)\.linux-i686\.tar\.bz2'),
+    'linux64': (LinuxArtifactJob, 'public/build/firefox-(.*)\.linux-x86_64\.tar\.bz2'),
     'macosx64': (MacArtifactJob, 'public/build/firefox-(.*)\.mac\.dmg'),
+    'win32': (WinArtifactJob, 'public/build/firefox-(.*)\.win32.zip'),
+    'win64': (WinArtifactJob, 'public/build/firefox-(.*)\.win64.zip'),
 }
 
 def get_job_details(job, log=None):
@@ -342,12 +408,39 @@ class PushHeadCache(CacheManager):
 
     @cachedmethod(operator.attrgetter('_cache'))
     def pushheads(self, tree, parent):
-        pushheads = subprocess.check_output([self._hg, 'log',
+        try:
+            pushheads = subprocess.check_output([self._hg, 'log',
+                '--template', '{node}\n',
+                '-r', 'last(pushhead("{tree}") and ::"{parent}", {num})'.format(
+                    tree=tree, parent=parent, num=NUM_PUSHHEADS_TO_QUERY_PER_PARENT)])
+            # Filter blank lines.
+            pushheads = [ pushhead for pushhead in pushheads.strip().split('\n') if pushhead ]
+            if pushheads:
+                return pushheads
+        except subprocess.CalledProcessError as e:
+            # Probably don't have the mozext extension installed.
+            ret = subprocess.call([self._hg, 'showconfig', 'extensions.mozext'])
+            if ret:
+                raise Exception('Could not find candidate pushheads.\n\n'
+                                'You need to enable the "mozext" hg extension: '
+                                'see https://developer.mozilla.org/en-US/docs/Artifact_builds')
+            raise e
+
+        # Probably don't have the pushlog database present locally.  Check.
+        tree_pushheads = subprocess.check_output([self._hg, 'log',
             '--template', '{node}\n',
-            '-r', 'last(pushhead("{tree}") & ::"{parent}", {num})'.format(
-                tree=tree, parent=parent, num=NUM_PUSHHEADS_TO_QUERY_PER_PARENT)])
-        pushheads = pushheads.strip().split('\n')
-        return pushheads
+            '-r', 'last(pushhead("{tree}"))'.format(tree=tree)])
+        # Filter blank lines.
+        tree_pushheads = [ pushhead for pushhead in tree_pushheads.strip().split('\n') if pushhead ]
+        if tree_pushheads:
+            # Okay, we have some pushheads but no candidates.  This can happen
+            # for legitimate reasons: old revisions with no upstream builds
+            # remaining; or new revisions that don't have upstream builds yet.
+            return []
+
+        raise Exception('Could not find any pushheads for tree "{tree}".\n\n'
+                        'Try running |hg pushlogsync|; '
+                        'see https://developer.mozilla.org/en-US/docs/Artifact_builds'.format(tree=tree))
 
 
 class TaskCache(CacheManager):
@@ -516,7 +609,7 @@ class Artifacts(object):
                 if info.filename.endswith('.ini'):
                     continue
                 n = mozpath.join(bindir, info.filename)
-                fh = FileAvoidWrite(n, mode='r')
+                fh = FileAvoidWrite(n, mode='rb')
                 shutil.copyfileobj(zf.open(info), fh)
                 file_existed, file_updated = fh.close()
                 self.log(logging.INFO, 'artifact',
diff --git a/python/mozbuild/mozbuild/mach_commands.py b/python/mozbuild/mozbuild/mach_commands.py
index e446e09e45d..14d4c488b28 100644
--- a/python/mozbuild/mozbuild/mach_commands.py
+++ b/python/mozbuild/mozbuild/mach_commands.py
@@ -633,7 +633,7 @@ class Build(MachCommandBase):
         self.log(logging.INFO, 'artifact',
                  {}, "Running |mach artifact install|.")
         args = [os.path.join(self.topsrcdir, 'mach'), 'artifact', 'install']
-        self._run_command_in_srcdir(args=args,
+        self._run_command_in_srcdir(args=args, require_unix_environment=True,
             pass_thru=True, ensure_exit_code=True)
 
 @CommandProvider
@@ -1397,10 +1397,19 @@ class MachDebug(MachCommandBase):
 class ArtifactSubCommand(SubCommand):
     def __call__(self, func):
         after = SubCommand.__call__(self, func)
+        jobchoices = {
+            'android-api-11',
+            'android-x86',
+            'linux',
+            'linux64',
+            'macosx64',
+            'win32',
+            'win64'
+        }
         args = [
             CommandArgument('--tree', metavar='TREE', type=str,
                 help='Firefox tree.'),
-            CommandArgument('--job', metavar='JOB', choices=['android-api-11', 'android-x86', 'macosx64'],
+            CommandArgument('--job', metavar='JOB', choices=jobchoices,
                 help='Build job.'),
             CommandArgument('--verbose', '-v', action='store_true',
                 help='Print verbose output.'),
@@ -1446,7 +1455,10 @@ class PackageFrontend(MachCommandBase):
         cache_dir = os.path.join(state_dir, 'package-frontend')
 
         import which
-        hg = which.which('hg')
+        if self._is_windows():
+          hg = which.which('hg.exe')
+        else:
+          hg = which.which('hg')
 
         # Absolutely must come after the virtualenv is populated!
         from mozbuild.artifacts import Artifacts
@@ -1460,12 +1472,16 @@ class PackageFrontend(MachCommandBase):
             return (tree, job)
         if self.substs.get('MOZ_BUILD_APP', '') == 'mobile/android':
             if self.substs['ANDROID_CPU_ARCH'] == 'x86':
-                return (tree, 'android-x86')
-            return (tree, 'android-api-11')
+                return tree, 'android-x86'
+            return tree, 'android-api-11'
+        # TODO: check for 32/64 bit builds.  We'd like to use HAVE_64BIT_BUILD
+        # but that relies on the compile environment.
+        if self.defines.get('XP_LINUX', False):
+            return tree, 'linux64'
         if self.defines.get('XP_MACOSX', False):
-            # TODO: check for 64 bit builds.  We'd like to use HAVE_64BIT_BUILD
-            # but that relies on the compile environment.
-            return (tree, 'macosx64')
+            return tree, 'macosx64'
+        if self.defines.get('XP_WIN', False):
+            return tree, 'win32'
         raise Exception('Cannot determine default tree and job for |mach artifact|!')
 
     @ArtifactSubCommand('artifact', 'install',
diff --git a/python/mozbuild/mozbuild/util.py b/python/mozbuild/mozbuild/util.py
index ddd4613a1fa..7c092f4b2f8 100644
--- a/python/mozbuild/mozbuild/util.py
+++ b/python/mozbuild/mozbuild/util.py
@@ -166,7 +166,12 @@ class FileAvoidWrite(BytesIO):
                 existing.close()
 
         ensureParentDir(self.name)
-        with open(self.name, 'w') as file:
+        # Maintain 'b' if specified.  'U' only applies to modes starting with
+        # 'r', so it is dropped.
+        writemode = 'w'
+        if 'b' in self.mode:
+            writemode += 'b'
+        with open(self.name, writemode) as file:
             file.write(buf)
 
         if self._capture_diff:
diff --git a/testing/mozharness/configs/b2g/desktop_windows32.py b/testing/mozharness/configs/b2g/desktop_windows32.py
index ffbe5c75ad9..2502da5f30e 100644
--- a/testing/mozharness/configs/b2g/desktop_windows32.py
+++ b/testing/mozharness/configs/b2g/desktop_windows32.py
@@ -75,7 +75,7 @@ config = {
         'HG_SHARE_BASE_DIR': 'C:/builds/hg-shared',
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'MOZ_OBJDIR': 'obj-firefox',
-        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/nsis-2.46u;C:/mozilla-build/python27;'
+        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/python27;'
                 'C:/mozilla-build/buildbotve/scripts;'
                 '%s' % (os.environ.get('path')),
         'PDBSTR_PATH': '/c/Program Files (x86)/Windows Kits/8.0/Debuggers/x64/srcsrv/pdbstr.exe',
diff --git a/testing/mozharness/configs/builds/releng_base_windows_32_builds.py b/testing/mozharness/configs/builds/releng_base_windows_32_builds.py
index b79a6a13fd3..82a1fd73ec7 100644
--- a/testing/mozharness/configs/builds/releng_base_windows_32_builds.py
+++ b/testing/mozharness/configs/builds/releng_base_windows_32_builds.py
@@ -76,7 +76,7 @@ config = {
         'HG_SHARE_BASE_DIR': 'C:/builds/hg-shared',
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'MOZ_OBJDIR': 'obj-firefox',
-        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/nsis-2.46u;C:/mozilla-build/python27;'
+        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/python27;'
                 'C:/mozilla-build/buildbotve/scripts;'
                 '%s' % (os.environ.get('path')),
         'PDBSTR_PATH': '/c/Program Files (x86)/Windows Kits/8.0/Debuggers/x64/srcsrv/pdbstr.exe',
diff --git a/testing/mozharness/configs/builds/releng_base_windows_64_builds.py b/testing/mozharness/configs/builds/releng_base_windows_64_builds.py
index 9f93d15d55b..2afc99d9fbb 100644
--- a/testing/mozharness/configs/builds/releng_base_windows_64_builds.py
+++ b/testing/mozharness/configs/builds/releng_base_windows_64_builds.py
@@ -75,7 +75,8 @@ config = {
         'HG_SHARE_BASE_DIR': 'C:/builds/hg-shared',
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'MOZ_OBJDIR': 'obj-firefox',
-        'PATH': 'C:/mozilla-build/python27;C:/mozilla-build/buildbotve/scripts;'
+        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/python27;'
+                'C:/mozilla-build/buildbotve/scripts;'
                 '%s' % (os.environ.get('path')),
         'PDBSTR_PATH': '/c/Program Files (x86)/Windows Kits/8.0/Debuggers/x64/srcsrv/pdbstr.exe',
         'PROPERTIES_FILE': os.path.join(os.getcwd(), 'buildprops.json'),
diff --git a/testing/mozharness/configs/builds/releng_sub_windows_configs/32_debug.py b/testing/mozharness/configs/builds/releng_sub_windows_configs/32_debug.py
index ce86ee84e9f..3792bf60aca 100644
--- a/testing/mozharness/configs/builds/releng_sub_windows_configs/32_debug.py
+++ b/testing/mozharness/configs/builds/releng_sub_windows_configs/32_debug.py
@@ -26,7 +26,7 @@ config = {
         'MOZ_AUTOMATION': '1',
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'MOZ_OBJDIR': 'obj-firefox',
-        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/nsis-2.46u;C:/mozilla-build/python27;'
+        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/python27;'
                 'C:/mozilla-build/buildbotve/scripts;'
                 '%s' % (os.environ.get('path')),
         'PROPERTIES_FILE': os.path.join(os.getcwd(), 'buildprops.json'),
diff --git a/testing/mozharness/configs/builds/releng_sub_windows_configs/32_mulet.py b/testing/mozharness/configs/builds/releng_sub_windows_configs/32_mulet.py
index 9340d712a3e..c7cf1abd171 100644
--- a/testing/mozharness/configs/builds/releng_sub_windows_configs/32_mulet.py
+++ b/testing/mozharness/configs/builds/releng_sub_windows_configs/32_mulet.py
@@ -25,7 +25,7 @@ config = {
         'MOZ_AUTOMATION': '1',
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'MOZ_OBJDIR': 'obj-firefox',
-        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/nsis-2.46u;C:/mozilla-build/python27;'
+        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/python27;'
                 'C:/mozilla-build/buildbotve/scripts;'
                 '%s' % (os.environ.get('path')),
         'PROPERTIES_FILE': os.path.join(os.getcwd(), 'buildprops.json'),
diff --git a/testing/mozharness/configs/builds/releng_sub_windows_configs/64_debug.py b/testing/mozharness/configs/builds/releng_sub_windows_configs/64_debug.py
index a176f03ec4f..6f97da0dab8 100644
--- a/testing/mozharness/configs/builds/releng_sub_windows_configs/64_debug.py
+++ b/testing/mozharness/configs/builds/releng_sub_windows_configs/64_debug.py
@@ -25,7 +25,8 @@ config = {
         'MOZ_AUTOMATION': '1',
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'MOZ_OBJDIR': 'obj-firefox',
-        'PATH': 'C:/mozilla-build/python27;C:/mozilla-build/buildbotve/scripts;'
+        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/python27;'
+                'C:/mozilla-build/buildbotve/scripts;'
                 '%s' % (os.environ.get('path')),
         'PROPERTIES_FILE': os.path.join(os.getcwd(), 'buildprops.json'),
         'TINDERBOX_OUTPUT': '1',
diff --git a/testing/mozharness/configs/builds/releng_sub_windows_configs/64_graphene.py b/testing/mozharness/configs/builds/releng_sub_windows_configs/64_graphene.py
index 448427f62bb..87d61992441 100644
--- a/testing/mozharness/configs/builds/releng_sub_windows_configs/64_graphene.py
+++ b/testing/mozharness/configs/builds/releng_sub_windows_configs/64_graphene.py
@@ -25,7 +25,7 @@ config = {
         'MOZ_AUTOMATION': '1',
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'MOZ_OBJDIR': 'obj-graphene',
-        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/nsis-2.46u;C:/mozilla-build/python27;'
+        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/python27;'
                 'C:/mozilla-build/buildbotve/scripts;'
                 '%s' % (os.environ.get('path')),
         'PROPERTIES_FILE': os.path.join(os.getcwd(), 'buildprops.json'),
diff --git a/testing/mozharness/configs/builds/releng_sub_windows_configs/64_horizon.py b/testing/mozharness/configs/builds/releng_sub_windows_configs/64_horizon.py
index bc4b702ad8e..ce9758504f4 100644
--- a/testing/mozharness/configs/builds/releng_sub_windows_configs/64_horizon.py
+++ b/testing/mozharness/configs/builds/releng_sub_windows_configs/64_horizon.py
@@ -25,7 +25,7 @@ config = {
         'MOZ_AUTOMATION': '1',
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'MOZ_OBJDIR': 'obj-horizon',
-        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/nsis-2.46u;C:/mozilla-build/python27;'
+        'PATH': 'C:/mozilla-build/nsis-3.0b1;C:/mozilla-build/python27;'
                 'C:/mozilla-build/buildbotve/scripts;'
                 '%s' % (os.environ.get('path')),
         'PROPERTIES_FILE': os.path.join(os.getcwd(), 'buildprops.json'),
diff --git a/toolkit/components/search/nsSearchService.js b/toolkit/components/search/nsSearchService.js
index 30cb26237ba..0b50401b4db 100644
--- a/toolkit/components/search/nsSearchService.js
+++ b/toolkit/components/search/nsSearchService.js
@@ -924,21 +924,6 @@ function getLocalizedPref(aPrefName, aDefault) {
   return aDefault;
 }
 
-/**
- * Wrapper for nsIPrefBranch::setComplexValue.
- * @param aPrefName
- *        The name of the pref to set.
- */
-function setLocalizedPref(aPrefName, aValue) {
-  const nsIPLS = Ci.nsIPrefLocalizedString;
-  try {
-    var pls = Components.classes["@mozilla.org/pref-localizedstring;1"]
-                        .createInstance(Ci.nsIPrefLocalizedString);
-    pls.data = aValue;
-    Services.prefs.setComplexValue(aPrefName, nsIPLS, pls);
-  } catch (ex) {}
-}
-
 /**
  * Wrapper for nsIPrefBranch::getBoolPref.
  * @param aPrefName
@@ -3122,7 +3107,6 @@ SearchService.prototype = {
         this._engines = {};
         this.__sortedEngines = null;
         this._currentEngine = null;
-        this._defaultEngine = null;
         this._visibleDefaultEngines = [];
         this._metaData = {};
         this._cacheFileJSON = null;
@@ -3987,10 +3971,6 @@ SearchService.prototype = {
       this._currentEngine = null;
     }
 
-    if (engineToRemove == this.defaultEngine) {
-      this._defaultEngine = null;
-    }
-
     if (engineToRemove._readOnly) {
       // Just hide it (the "hidden" setter will notify) and remove its alias to
       // avoid future conflicts with other engines.
@@ -4082,52 +4062,10 @@ SearchService.prototype = {
     }
   },
 
-  get defaultEngine() {
-    this._ensureInitialized();
-    if (!this._defaultEngine) {
-      let defPref = getGeoSpecificPrefName(BROWSER_SEARCH_PREF + "defaultenginename");
-      let defaultEngine = this.getEngineByName(getLocalizedPref(defPref, ""))
-      if (!defaultEngine)
-        defaultEngine = this._getSortedEngines(false)[0] || null;
-      this._defaultEngine = defaultEngine;
-    }
-    if (this._defaultEngine.hidden)
-      return this._getSortedEngines(false)[0];
-    return this._defaultEngine;
-  },
+  get defaultEngine() { return this.currentEngine; },
 
   set defaultEngine(val) {
-    this._ensureInitialized();
-    // Sometimes we get wrapped nsISearchEngine objects (external XPCOM callers),
-    // and sometimes we get raw Engine JS objects (callers in this file), so
-    // handle both.
-    if (!(val instanceof Ci.nsISearchEngine) && !(val instanceof Engine))
-      FAIL("Invalid argument passed to defaultEngine setter");
-
-    let newDefaultEngine = this.getEngineByName(val.name);
-    if (!newDefaultEngine)
-      FAIL("Can't find engine in store!", Cr.NS_ERROR_UNEXPECTED);
-
-    if (newDefaultEngine == this._defaultEngine)
-      return;
-
-    this._defaultEngine = newDefaultEngine;
-
-    let defPref = getGeoSpecificPrefName(BROWSER_SEARCH_PREF + "defaultenginename");
-
-    // If we change the default engine in the future, that change should impact
-    // users who have switched away from and then back to the build's "default"
-    // engine. So clear the user pref when the defaultEngine is set to the
-    // build's default engine, so that the defaultEngine getter falls back to
-    // whatever the default is.
-    if (this._defaultEngine == this._originalDefaultEngine) {
-      Services.prefs.clearUserPref(defPref);
-    }
-    else {
-      setLocalizedPref(defPref, this._defaultEngine.name);
-    }
-
-    notifyAction(this._defaultEngine, SEARCH_ENGINE_DEFAULT);
+    this.currentEngine = val;
   },
 
   get currentEngine() {
@@ -4204,6 +4142,7 @@ SearchService.prototype = {
     this.setGlobalAttr("current", newName);
     this.setGlobalAttr("hash", getVerificationHash(newName));
 
+    notifyAction(this._currentEngine, SEARCH_ENGINE_DEFAULT);
     notifyAction(this._currentEngine, SEARCH_ENGINE_CURRENT);
   },
 
diff --git a/toolkit/components/search/tests/xpcshell/head_search.js b/toolkit/components/search/tests/xpcshell/head_search.js
index cd7071faf30..f7998e98d3f 100644
--- a/toolkit/components/search/tests/xpcshell/head_search.js
+++ b/toolkit/components/search/tests/xpcshell/head_search.js
@@ -458,18 +458,14 @@ function installTestEngine() {
 }
 
 /**
- * Wrapper for nsIPrefBranch::setComplexValue.
+ * Set a localized preference on the default branch
  * @param aPrefName
  *        The name of the pref to set.
  */
-function setLocalizedPref(aPrefName, aValue) {
-  const nsIPLS = Ci.nsIPrefLocalizedString;
-  try {
-    var pls = Components.classes["@mozilla.org/pref-localizedstring;1"]
-                        .createInstance(Ci.nsIPrefLocalizedString);
-    pls.data = aValue;
-    Services.prefs.setComplexValue(aPrefName, nsIPLS, pls);
-  } catch (ex) {}
+function setLocalizedDefaultPref(aPrefName, aValue) {
+  let value = "data:text/plain," + BROWSER_SEARCH_PREF + aPrefName + "=" + aValue;
+  Services.prefs.getDefaultBranch(BROWSER_SEARCH_PREF)
+          .setCharPref(aPrefName, value);
 }
 
 
@@ -496,8 +492,8 @@ function setUpGeoDefaults() {
 
   do_get_file("data/engine2.xml").copyTo(engineDir, "engine2.xml");
 
-  setLocalizedPref("browser.search.defaultenginename",    "Test search engine");
-  setLocalizedPref("browser.search.defaultenginename.US", "A second test engine");
+  setLocalizedDefaultPref("defaultenginename",    "Test search engine");
+  setLocalizedDefaultPref("defaultenginename.US", "A second test engine");
 
   do_register_cleanup(function() {
     removeMetadata();
diff --git a/toolkit/components/search/tests/xpcshell/test_defaultEngine.js b/toolkit/components/search/tests/xpcshell/test_defaultEngine.js
index 26645fec264..13d9922dee5 100644
--- a/toolkit/components/search/tests/xpcshell/test_defaultEngine.js
+++ b/toolkit/components/search/tests/xpcshell/test_defaultEngine.js
@@ -17,13 +17,15 @@ function run_test() {
 }
 
 add_task(function* test_defaultEngine() {
+  let search = Services.search;
+
+  let originalDefault = search.defaultEngine;
+
   let [engine1, engine2] = yield addTestEngines([
     { name: "Test search engine", xmlFileName: "engine.xml" },
     { name: "A second test engine", xmlFileName: "engine2.xml" },
   ]);
 
-  let search = Services.search;
-
   search.defaultEngine = engine1;
   do_check_eq(search.defaultEngine, engine1);
   search.defaultEngine = engine2
@@ -32,22 +34,18 @@ add_task(function* test_defaultEngine() {
   do_check_eq(search.defaultEngine, engine1);
 
   // Test that hiding the currently-default engine affects the defaultEngine getter
-  // (when the default is hidden, we fall back to the first in the list, so move
-  // our second engine to that position)
-  search.moveEngine(engine2, 0);
+  // We fallback first to the original default...
   engine1.hidden = true;
-  do_check_eq(search.defaultEngine, engine2);
+  do_check_eq(search.defaultEngine, originalDefault);
 
-  // Test that the default engine is restored when it is unhidden
-  engine1.hidden = false;
-  do_check_eq(search.defaultEngine, engine1);
+  // ... and then to the first visible engine in the list, so move our second
+  // engine to that position.
+  search.moveEngine(engine2, 0);
+  originalDefault.hidden = true;
+  do_check_eq(search.defaultEngine, engine2);
 
   // Test that setting defaultEngine to an already-hidden engine works, but
   // doesn't change the return value of the getter
-  engine2.hidden = true;
-  search.moveEngine(engine1, 0)
-  search.defaultEngine = engine2;
-  do_check_eq(search.defaultEngine, engine1);
-  engine2.hidden = false;
+  search.defaultEngine = engine1;
   do_check_eq(search.defaultEngine, engine2);
 });
diff --git a/toolkit/components/search/tests/xpcshell/test_selectedEngine.js b/toolkit/components/search/tests/xpcshell/test_selectedEngine.js
index 2601581becb..a1c0f363e4d 100644
--- a/toolkit/components/search/tests/xpcshell/test_selectedEngine.js
+++ b/toolkit/components/search/tests/xpcshell/test_selectedEngine.js
@@ -48,11 +48,8 @@ add_task(function* test_persistAcrossRestarts() {
   do_check_eq(Services.search.currentEngine.name, kTestEngineName);
 
   // Cleanup (set the engine back to default).
-  Services.search.currentEngine = Services.search.defaultEngine;
-  // This check is no longer valid with bug 1102416's patch - defaultEngine
-  // is not based on the same value as _originalDefaultEngine in non-Firefox
-  // users of the search service.
-  //do_check_eq(Services.search.currentEngine.name, getDefaultEngineName());
+  Services.search.resetToOriginalDefaultEngine();
+  do_check_eq(Services.search.currentEngine.name, getDefaultEngineName());
 });
 
 // An engine set without a valid hash should be ignored.
diff --git a/toolkit/components/telemetry/TelemetryEnvironment.jsm b/toolkit/components/telemetry/TelemetryEnvironment.jsm
index 283ce5029ed..795f0e5e0df 100644
--- a/toolkit/components/telemetry/TelemetryEnvironment.jsm
+++ b/toolkit/components/telemetry/TelemetryEnvironment.jsm
@@ -794,7 +794,7 @@ EnvironmentCache.prototype = {
       if (!Preferences.isSet(pref)) {
         continue;
       }
-      
+
       // Check the policy for the preference and decide if we need to store its value
       // or whether it changed from the default value.
       let prefValue = undefined;
@@ -863,7 +863,7 @@ EnvironmentCache.prototype = {
     this._log.trace("observe - aTopic: " + aTopic + ", aData: " + aData);
     switch (aTopic) {
       case SEARCH_ENGINE_MODIFIED_TOPIC:
-        if (aData != "engine-default" && aData != "engine-current") {
+        if (aData != "engine-current") {
           return;
         }
         // Record the new default search choice and send the change notification.
diff --git a/toolkit/components/telemetry/tests/unit/test_TelemetryEnvironment.js b/toolkit/components/telemetry/tests/unit/test_TelemetryEnvironment.js
index c86756908b6..68b9ea08a17 100644
--- a/toolkit/components/telemetry/tests/unit/test_TelemetryEnvironment.js
+++ b/toolkit/components/telemetry/tests/unit/test_TelemetryEnvironment.js
@@ -1115,10 +1115,10 @@ add_task(function* test_defaultSearchEngine() {
   for (let engine of Services.search.getEngines()) {
     Services.search.removeEngine(engine);
   }
-  // The search service does not notify "engine-default" when removing a default engine.
+  // The search service does not notify "engine-current" when removing a default engine.
   // Manually force the notification.
   // TODO: remove this when bug 1165341 is resolved.
-  Services.obs.notifyObservers(null, "browser-search-engine-modified", "engine-default");
+  Services.obs.notifyObservers(null, "browser-search-engine-modified", "engine-current");
 
   // Then check that no default engine is reported if none is available.
   data = TelemetryEnvironment.currentEnvironment;