--- a/accessible/windows/msaa/AccessibleWrap.cpp
+++ b/accessible/windows/msaa/AccessibleWrap.cpp
@@ -1449,16 +1449,20 @@ GetProxiedAccessibleInSubtree(const DocA
   }
 
   MOZ_ASSERT(aDoc->IsTopLevel());
   if (!aDoc->IsTopLevel()) {
     return nullptr;
   }
 
   wrapper->GetNativeInterface(getter_AddRefs(comProxy));
+  MOZ_ASSERT(comProxy);
+  if (!comProxy) {
+    return nullptr;
+  }
 
   RefPtr<IDispatch> disp;
   if (FAILED(comProxy->get_accChild(aVarChild, getter_AddRefs(disp)))) {
     return nullptr;
   }
 
   return disp.forget();
 }

--- a/browser/base/content/browser-devedition.js
+++ b/browser/base/content/browser-devedition.js
@@ -20,16 +20,17 @@ var DevEdition = {
     let theme = LightweightThemeManager.currentTheme;
     return theme && theme.id == "firefox-devedition@mozilla.org";
   },
 
   init: function () {
     this.initialized = true;
     Services.prefs.addObserver(this._devtoolsThemePrefName, this, false);
     Services.obs.addObserver(this, "lightweight-theme-styling-update", false);
+    Services.obs.addObserver(this, "lightweight-theme-window-updated", false);
     this._updateDevtoolsThemeAttribute();
 
     if (this.isThemeCurrentlyApplied) {
       this._toggleStyleSheet(true);
     }
   },
 
   createStyleSheet: function() {
@@ -44,16 +45,18 @@ var DevEdition = {
   observe: function (subject, topic, data) {
     if (topic == "lightweight-theme-styling-update") {
       let newTheme = JSON.parse(data);
       if (newTheme && newTheme.id == "firefox-devedition@mozilla.org") {
         this._toggleStyleSheet(true);
       } else {
         this._toggleStyleSheet(false);
       }
+    } else if (topic == "lightweight-theme-window-updated" && subject == window) {
+      this._updateLWTBrightness();
     }
 
     if (topic == "nsPref:changed" && data == this._devtoolsThemePrefName) {
       this._updateDevtoolsThemeAttribute();
     }
   },
 
   _inferBrightness: function() {
@@ -62,24 +65,33 @@ var DevEdition = {
     if (this.isStyleSheetEnabled &&
         document.documentElement.getAttribute("devtoolstheme") == "dark") {
       document.documentElement.setAttribute("brighttitlebarforeground", "true");
     } else {
       document.documentElement.removeAttribute("brighttitlebarforeground");
     }
   },
 
+  _updateLWTBrightness() {
+    if (this.isThemeCurrentlyApplied) {
+      let devtoolsTheme = Services.prefs.getCharPref(this._devtoolsThemePrefName);
+      let textColor = devtoolsTheme == "dark" ? "bright" : "dark";
+      document.documentElement.setAttribute("lwthemetextcolor", textColor);
+    }
+  },
+
   _updateDevtoolsThemeAttribute: function() {
     // Set an attribute on root element to make it possible
     // to change colors based on the selected devtools theme.
     let devtoolsTheme = Services.prefs.getCharPref(this._devtoolsThemePrefName);
     if (devtoolsTheme != "dark") {
       devtoolsTheme = "light";
     }
     document.documentElement.setAttribute("devtoolstheme", devtoolsTheme);
+    this._updateLWTBrightness();
     this._inferBrightness();
   },
 
   handleEvent: function(e) {
     if (e.type === "load") {
       this.styleSheet.removeEventListener("load", this);
       this.refreshBrowserDisplay();
     }
@@ -108,16 +120,17 @@ var DevEdition = {
       this.styleSheet.sheet.disabled = true;
       this.refreshBrowserDisplay();
     }
   },
 
   uninit: function () {
     Services.prefs.removeObserver(this._devtoolsThemePrefName, this);
     Services.obs.removeObserver(this, "lightweight-theme-styling-update", false);
+    Services.obs.removeObserver(this, "lightweight-theme-window-updated", false);
     if (this.styleSheet) {
       this.styleSheet.removeEventListener("load", this);
     }
     this.styleSheet = null;
   }
 };
 
 // If the DevEdition theme is going to be applied in gBrowserInit.onLoad,

--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -3570,36 +3570,28 @@ const BrowserSearch = {
         }
         win = window.openDialog(getBrowserURL(), "_blank",
                                 "chrome,all,dialog=no", "about:blank");
         Services.obs.addObserver(observer, "browser-delayed-startup-finished", false);
       }
       return;
     }
 
-    let openSearchPageIfFieldIsNotActive = function(aSearchBar) {
+    let focusUrlBarIfSearchFieldIsNotActive = function(aSearchBar) {
       if (!aSearchBar || document.activeElement != aSearchBar.textbox.inputField) {
-        let url = gBrowser.currentURI.spec.toLowerCase();
-        let mm = gBrowser.selectedBrowser.messageManager;
-        let newTabRemoted = Services.prefs.getBoolPref("browser.newtabpage.remote");
-        let localNewTabEnabled = url === "about:newtab" && !newTabRemoted && NewTabUtils.allPages.enabled;
-        if (url === "about:home" || localNewTabEnabled) {
-          ContentSearch.focusInput(mm);
-        } else {
-          openUILinkIn("about:home", "current");
-        }
+        focusAndSelectUrlBar();
       }
     };
 
     let searchBar = this.searchBar;
     let placement = CustomizableUI.getPlacementOfWidget("search-container");
     let focusSearchBar = () => {
       searchBar = this.searchBar;
       searchBar.select();
-      openSearchPageIfFieldIsNotActive(searchBar);
+      focusUrlBarIfSearchFieldIsNotActive(searchBar);
     };
     if (placement && placement.area == CustomizableUI.AREA_PANEL) {
       // The panel is not constructed until the first time it is shown.
       PanelUI.show().then(focusSearchBar);
       return;
     }
     if (placement && placement.area == CustomizableUI.AREA_NAVBAR && searchBar &&
         searchBar.parentNode.getAttribute("overflowedItem") == "true") {
@@ -3609,17 +3601,17 @@ const BrowserSearch = {
       });
       return;
     }
     if (searchBar) {
       if (window.fullScreen)
         FullScreen.showNavToolbox();
       searchBar.select();
     }
-    openSearchPageIfFieldIsNotActive(searchBar);
+    focusUrlBarIfSearchFieldIsNotActive(searchBar);
   },
 
   /**
    * Loads a search results page, given a set of search terms. Uses the current
    * engine if the search bar is visible, or the default engine otherwise.
    *
    * @param searchText
    *        The search terms to use for the search.

--- a/browser/base/content/test/general/browser_aboutHome.js
+++ b/browser/base/content/test/general/browser_aboutHome.js
@@ -471,44 +471,16 @@ add_task(function* () {
       yield ContentTaskUtils.waitForCondition(() => doc.activeElement === searchInput,
         "Search input should be the active element.");
       is(searchInput.value, "a", "Search input should be 'a'.");
     });
   });
 });
 
 add_task(function* () {
-  info("Cmd+k should focus the search box in the page when the search box in the toolbar is absent");
-
-  // Remove the search bar from toolbar
-  CustomizableUI.removeWidgetFromArea("search-container");
-
-  yield BrowserTestUtils.withNewTab({ gBrowser, url: "about:home" }, function* (browser) {
-    yield BrowserTestUtils.synthesizeMouseAtCenter("#brandLogo", {}, browser);
-    yield ContentTask.spawn(browser, null, function* () {
-      let doc = content.document;
-      isnot(doc.getElementById("searchText"), doc.activeElement,
-        "Search input should not be the active element.");
-    });
-
-    EventUtils.synthesizeKey("k", { accelKey: true });
-
-    yield ContentTask.spawn(browser, null, function* () {
-      let doc = content.document;
-      let searchInput = doc.getElementById("searchText");
-
-      yield ContentTaskUtils.waitForCondition(() => doc.activeElement === searchInput,
-        "Search input should be the active element.");
-    });
-  });
-
-  CustomizableUI.reset();
-});
-
-add_task(function* () {
   info("Cmd+k should focus the search box in the toolbar when it's present");
 
   yield BrowserTestUtils.withNewTab({ gBrowser, url: "about:home" }, function* (browser) {
     yield BrowserTestUtils.synthesizeMouseAtCenter("#brandLogo", {}, browser);
 
     let doc = window.document;
     let searchInput = doc.getElementById("searchbar").textbox.inputField;
     isnot(searchInput, doc.activeElement, "Search bar should not be the active element.");

--- a/browser/base/content/test/newtab/browser.ini
+++ b/browser/base/content/test/newtab/browser.ini
@@ -40,11 +40,12 @@ support-files =
   searchEngineNoLogo.xml
   searchEngineFavicon.xml
   searchEngine1xLogo.xml
   searchEngine2xLogo.xml
   searchEngine1x2xLogo.xml
   ../general/searchSuggestionEngine.xml
   ../general/searchSuggestionEngine.sjs
 [browser_newtab_sponsored_icon_click.js]
+skip-if = true # Bug 1314619
 [browser_newtab_undo.js]
 [browser_newtab_unpin.js]
 [browser_newtab_update.js]

--- a/browser/base/content/test/newtab/browser_newtab_search.js
+++ b/browser/base/content/test/newtab/browser_newtab_search.js
@@ -173,75 +173,16 @@ add_task(function* () {
   EventUtils.synthesizeKey("a", { accelKey: true });
   EventUtils.synthesizeKey("VK_DELETE", {});
 
   yield ContentTask.spawn(gBrowser.selectedBrowser, {}, function* () {
     Assert.ok(content.document.getElementById("searchSuggestionTable").hidden,
       "Search suggestion table hidden");
   });
 
-  // Remove the search bar from toolbar
-  CustomizableUI.removeWidgetFromArea("search-container");
-  // Focus a different element than the search input from the page.
-  yield BrowserTestUtils.synthesizeMouseAtCenter("#newtab-customize-button", { }, gBrowser.selectedBrowser);
-
-  yield ContentTask.spawn(gBrowser.selectedBrowser, { }, function* () {
-    let input = content.document.getElementById("newtab-search-text");
-    Assert.notEqual(input, content.document.activeElement, "Search input should not be focused");
-  });
-
-  // Test that Ctrl/Cmd + K will focus the input field from the page.
-  let focusPromise = promiseSearchEvents(["FocusInput"]);
-  EventUtils.synthesizeKey("k", { accelKey: true });
-  yield focusPromise;
-
-  yield ContentTask.spawn(gBrowser.selectedBrowser, { }, function* () {
-    let input = content.document.getElementById("newtab-search-text");
-    Assert.equal(input, content.document.activeElement, "Search input should be focused");
-  });
-
-  // Reset changes made to toolbar
-  CustomizableUI.reset();
-
-  // Test that Ctrl/Cmd + K will focus the search bar from toolbar.
-  EventUtils.synthesizeKey("k", { accelKey: true });
-  let searchBar = document.getElementById("searchbar");
-  is(searchBar.textbox.inputField, document.activeElement, "Toolbar's search bar should be focused");
-
-  // Test that Ctrl/Cmd + K will focus the search bar from a new about:home page if
-  // the newtab is disabled from `NewTabUtils.allPages.enabled`.
-  let tab = yield* addNewTabPageTab();
-  // Remove the search bar from toolbar
-  CustomizableUI.removeWidgetFromArea("search-container");
-  NewTabUtils.allPages.enabled = false;
-  EventUtils.synthesizeKey("k", { accelKey: true });
-
-
-  let aboutHomeLoaded = new Promise(resolve => {
-    tab.linkedBrowser.addEventListener("AboutHomeLoadSnippetsCompleted", function loadListener(event) {
-      tab.linkedBrowser.removeEventListener("AboutHomeLoadSnippetsCompleted", loadListener, true);
-      resolve();
-    }, true, true);
-  });
-
-  tab.linkedBrowser.loadURI("about:home");
-  yield aboutHomeLoaded;
-
-  yield ContentTask.spawn(gBrowser.selectedBrowser, { }, function* () {
-    Assert.equal(content.document.documentURI.toLowerCase(), "about:home",
-      "New tab's uri should be about:home");
-    let searchInput = content.document.getElementById("searchText");
-    Assert.equal(searchInput, content.document.activeElement,
-      "Search input must be the selected element");
-  });
-
-  NewTabUtils.allPages.enabled = true;
-  CustomizableUI.reset();
-  yield BrowserTestUtils.removeTab(gBrowser.selectedTab);
-
   // Done.  Revert the current engine and remove the new engines.
   searchEventsPromise = promiseSearchEvents(["CurrentEngine"]);
   Services.search.currentEngine = oldCurrentEngine;
   yield searchEventsPromise;
 
   let events = Array(gNewEngines.length).fill("CurrentState", 0, gNewEngines.length);
   searchEventsPromise = promiseSearchEvents(events);
 

--- a/browser/base/content/test/urlbar/browser.ini
+++ b/browser/base/content/test/urlbar/browser.ini
@@ -50,16 +50,17 @@ skip-if = os == 'linux' # Bug 1104755
 subsuite = clipboard
 support-files =
   authenticate.sjs
 [browser_urlbarDecode.js]
 [browser_urlbarDelete.js]
 [browser_urlbarEnter.js]
 [browser_urlbarEnterAfterMouseOver.js]
 skip-if = os == "linux" # Bug 1073339 - Investigate autocomplete test unreliability on Linux/e10s
+[browser_urlbarFocusedCmdK.js]
 [browser_urlbarHashChangeProxyState.js]
 [browser_urlbarKeepStateAcrossTabSwitches.js]
 [browser_urlbarOneOffs.js]
 [browser_urlbarPrivateBrowsingWindowChange.js]
 [browser_urlbarRaceWithTabs.js]
 [browser_urlbarRevert.js]
 [browser_urlbarSearchSingleWordNotification.js]
 [browser_urlbarSearchSuggestions.js]

--- a/browser/base/content/test/urlbar/browser_urlbarCopying.js
+++ b/browser/base/content/test/urlbar/browser_urlbarCopying.js
@@ -189,16 +189,11 @@ function testCopy(copyVal, targetValue, 
       gURLBar.select();
     }
 
     goDoCommand("cmd_copy");
   }, cb, cb);
 }
 
 function loadURL(aURL, aCB) {
-  gBrowser.selectedBrowser.addEventListener("load", function () {
-    gBrowser.selectedBrowser.removeEventListener("load", arguments.callee, true);
-    is(gBrowser.currentURI.spec, aURL, "loaded expected URL");
-    aCB();
-  }, true);
-
-  gBrowser.loadURI(aURL);
+  BrowserTestUtils.loadURI(gBrowser.selectedBrowser, aURL);
+  BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser, false, aURL).then(aCB);
 }

new file mode 100644
--- /dev/null
+++ b/browser/base/content/test/urlbar/browser_urlbarFocusedCmdK.js
@@ -0,0 +1,17 @@
+/* Any copyright is dedicated to the Public Domain.
+* http://creativecommons.org/publicdomain/zero/1.0/ */
+
+add_task(function*() {
+  // Remove the search bar from toolbar
+  CustomizableUI.removeWidgetFromArea("search-container");
+
+  // Test that Ctrl/Cmd + K will focus the url bar
+  let focusPromise = BrowserTestUtils.waitForEvent(gURLBar, "focus");
+  EventUtils.synthesizeKey("k", { accelKey: true });
+  yield focusPromise;
+  Assert.equal(document.activeElement, gURLBar.inputField, "URL Bar should be focused");
+
+  // Reset changes made to toolbar
+  CustomizableUI.reset();
+});
+

--- a/browser/components/customizableui/test/browser_901207_searchbar_in_panel.js
+++ b/browser/components/customizableui/test/browser_901207_searchbar_in_panel.js
@@ -1,25 +1,14 @@
 /* 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/. */
 
 "use strict";
 
-var openUILinkInCalled = false;
-var expectOpenUILinkInCall = false;
-this.originalOpenUILinkIn = openUILinkIn;
-openUILinkIn = (aUrl, aWhichTab) => {
-  is(aUrl, "about:home", "about:home should be requested to open.");
-  is(aWhichTab, "current", "Should use the current tab for the search page.");
-  openUILinkInCalled = true;
-  if (!expectOpenUILinkInCall) {
-    ok(false, "OpenUILinkIn was called when it shouldn't have been.");
-  }
-};
 logActiveElement();
 
 function* waitForSearchBarFocus()
 {
   let searchbar = document.getElementById("searchbar");
   yield waitForCondition(function () {
     logActiveElement();
     return document.activeElement === searchbar.textbox.inputField;
@@ -100,40 +89,16 @@ add_task(function*() {
   let placement = CustomizableUI.getPlacementOfWidget("search-container");
   is(placement.area, CustomizableUI.AREA_NAVBAR, "Should be in nav-bar");
 
   sendWebSearchKeyCommand();
 
   yield waitForSearchBarFocus();
 });
 
-// Ctrl+K should open the search page if the search bar has been customized out.
-add_task(function*() {
-  try {
-    expectOpenUILinkInCall = true;
-    CustomizableUI.removeWidgetFromArea("search-container");
-    let placement = CustomizableUI.getPlacementOfWidget("search-container");
-    is(placement, null, "Search container should be in palette");
-
-    openUILinkInCalled = false;
-
-    sendWebSearchKeyCommand();
-    yield waitForCondition(() => openUILinkInCalled);
-    ok(openUILinkInCalled, "The search page should have been opened.")
-    expectOpenUILinkInCall = false;
-  } catch (e) {
-    ok(false, e);
-  }
-  CustomizableUI.reset();
-});
-
-registerCleanupFunction(function() {
-  openUILinkIn = this.originalOpenUILinkIn;
-  delete this.originalOpenUILinkIn;
-});
 
 function sendWebSearchKeyCommand() {
   if (Services.appinfo.OS === "Darwin")
     EventUtils.synthesizeKey("k", { accelKey: true });
   else
     EventUtils.synthesizeKey("k", { ctrlKey: true });
 }
 

--- a/browser/components/preferences/in-content/tests/browser_security.js
+++ b/browser/components/preferences/in-content/tests/browser_security.js
@@ -118,13 +118,13 @@ add_task(function*() {
        "malware table doesn't include test-unwanted-simple");
     let sortedMalware = malwareTable.slice(0);
     sortedMalware.sort();
     Assert.deepEqual(malwareTable, sortedMalware, "malware table has been sorted");
 
     yield BrowserTestUtils.removeTab(gBrowser.selectedTab);
   }
 
-  yield checkPrefSwitch(true, true);
-  yield checkPrefSwitch(false, true);
-  yield checkPrefSwitch(true, false);
-  yield checkPrefSwitch(false, false);
+  yield* checkPrefSwitch(true, true);
+  yield* checkPrefSwitch(false, true);
+  yield* checkPrefSwitch(true, false);
+  yield* checkPrefSwitch(false, false);
 });

--- a/browser/components/sessionstore/ContentRestore.jsm
+++ b/browser/components/sessionstore/ContentRestore.jsm
@@ -19,17 +19,17 @@ XPCOMUtils.defineLazyModuleGetter(this, 
   "resource:///modules/sessionstore/PageStyle.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "ScrollPosition",
   "resource://gre/modules/ScrollPosition.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "SessionHistory",
   "resource:///modules/sessionstore/SessionHistory.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "SessionStorage",
   "resource:///modules/sessionstore/SessionStorage.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Utils",
-  "resource:///modules/sessionstore/Utils.jsm");
+  "resource://gre/modules/sessionstore/Utils.jsm");
 
 /**
  * This module implements the content side of session restoration. The chrome
  * side is handled by SessionStore.jsm. The functions in this module are called
  * by content-sessionStore.js based on messages received from SessionStore.jsm
  * (or, in one case, based on a "load" event). Each tab has its own
  * ContentRestore instance, constructed by content-sessionStore.js.
  *

--- a/browser/components/sessionstore/SessionCookies.jsm
+++ b/browser/components/sessionstore/SessionCookies.jsm
@@ -8,17 +8,17 @@ this.EXPORTED_SYMBOLS = ["SessionCookies
 
 const Cu = Components.utils;
 const Ci = Components.interfaces;
 
 Cu.import("resource://gre/modules/Services.jsm", this);
 Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
 
 XPCOMUtils.defineLazyModuleGetter(this, "Utils",
-  "resource:///modules/sessionstore/Utils.jsm");
+  "resource://gre/modules/sessionstore/Utils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "PrivacyLevel",
   "resource:///modules/sessionstore/PrivacyLevel.jsm");
 
 // MAX_EXPIRY should be 2^63-1, but JavaScript can't handle that precision.
 const MAX_EXPIRY = Math.pow(2, 62);
 
 /**
  * The external API implemented by the SessionCookies module.

--- a/browser/components/sessionstore/SessionHistory.jsm
+++ b/browser/components/sessionstore/SessionHistory.jsm
@@ -9,17 +9,17 @@ this.EXPORTED_SYMBOLS = ["SessionHistory
 const Cu = Components.utils;
 const Cc = Components.classes;
 const Ci = Components.interfaces;
 
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "Utils",
-  "resource:///modules/sessionstore/Utils.jsm");
+  "resource://gre/modules/sessionstore/Utils.jsm");
 
 function debug(msg) {
   Services.console.logStringMessage("SessionHistory: " + msg);
 }
 
 /**
  * The external API exported by this module.
  */

--- a/browser/components/sessionstore/SessionStore.jsm
+++ b/browser/components/sessionstore/SessionStore.jsm
@@ -175,17 +175,17 @@ XPCOMUtils.defineLazyModuleGetter(this, 
   "resource:///modules/ContentCrashHandlers.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "TabState",
   "resource:///modules/sessionstore/TabState.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "TabStateCache",
   "resource:///modules/sessionstore/TabStateCache.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "TabStateFlusher",
   "resource:///modules/sessionstore/TabStateFlusher.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Utils",
-  "resource:///modules/sessionstore/Utils.jsm");
+  "resource://gre/modules/sessionstore/Utils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "ViewSourceBrowser",
   "resource://gre/modules/ViewSourceBrowser.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "AsyncShutdown",
   "resource://gre/modules/AsyncShutdown.jsm");
 
 /**
  * |true| if we are in debug mode, |false| otherwise.
  * Debug mode is controlled by preference browser.sessionstore.debug

--- a/browser/components/sessionstore/TabState.jsm
+++ b/browser/components/sessionstore/TabState.jsm
@@ -12,17 +12,17 @@ Cu.import("resource://gre/modules/XPCOMU
 
 XPCOMUtils.defineLazyModuleGetter(this, "PrivacyFilter",
   "resource:///modules/sessionstore/PrivacyFilter.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "TabStateCache",
   "resource:///modules/sessionstore/TabStateCache.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "TabAttributes",
   "resource:///modules/sessionstore/TabAttributes.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Utils",
-  "resource:///modules/sessionstore/Utils.jsm");
+  "resource://gre/modules/sessionstore/Utils.jsm");
 
 /**
  * Module that contains tab state collection methods.
  */
 this.TabState = Object.freeze({
   update: function (browser, data) {
     TabStateInternal.update(browser, data);
   },

--- a/browser/components/sessionstore/moz.build
+++ b/browser/components/sessionstore/moz.build
@@ -41,13 +41,12 @@ EXTRA_JS_MODULES.sessionstore = [
     'SessionStore.jsm',
     'SessionWorker.js',
     'SessionWorker.jsm',
     'StartupPerformance.jsm',
     'TabAttributes.jsm',
     'TabState.jsm',
     'TabStateCache.jsm',
     'TabStateFlusher.jsm',
-    'Utils.jsm',
 ]
 
 with Files('**'):
     BUG_COMPONENT = ('Firefox', 'Session Restore')

--- a/browser/locales/filter.py
+++ b/browser/locales/filter.py
@@ -12,22 +12,19 @@ def test(mod, path, entity = None):
                  "other-licenses/branding/firefox",
                  "browser/branding/official",
                  "services/sync"):
     return "ignore"
   if mod not in ("browser", "extensions/spellcheck"):
     # we only have exceptions for browser and extensions/spellcheck
     return "error"
   if not entity:
-    # the only files to ignore are spell checkers and search
+    # the only files to ignore are spell checkers
     if mod == "extensions/spellcheck":
       return "ignore"
-    # browser
-    if (re.match(r"searchplugins\/.+\.xml", path)):
-      return "ignore"
     return "error"
   if mod == "extensions/spellcheck":
     # l10n ships en-US dictionary or something, do compare
     return "error"
   if path == "defines.inc":
     return "ignore" if entity == "MOZ_LANGPACK_CONTRIBUTORS" else "error"
 
   if mod == "browser" and path == "chrome/browser-region/region.properties":

--- a/browser/locales/jar.mn
+++ b/browser/locales/jar.mn
@@ -85,17 +85,17 @@
     locale/browser/syncSetup.dtd                (%chrome/browser/syncSetup.dtd)
     locale/browser/syncSetup.properties         (%chrome/browser/syncSetup.properties)
     locale/browser/syncGenericChange.properties         (%chrome/browser/syncGenericChange.properties)
     locale/browser/syncKey.dtd                  (%chrome/browser/syncKey.dtd)
     locale/browser/syncQuota.dtd                (%chrome/browser/syncQuota.dtd)
     locale/browser/syncQuota.properties         (%chrome/browser/syncQuota.properties)
 % resource search-plugins chrome://browser/locale/searchplugins/
 #if BUILD_FASTER
-    locale/browser/searchplugins/               (%searchplugins/*.xml)
+    locale/browser/searchplugins/               (searchplugins/*.xml)
     locale/browser/searchplugins/list.json      (search/list.json)
 #else
     locale/browser/searchplugins/               (.deps/generated_@AB_CD@/*.xml)
     locale/browser/searchplugins/list.json      (.deps/generated_@AB_CD@/list.json)
 #endif
 % locale browser-region @AB_CD@ %locale/browser-region/
     locale/browser-region/region.properties        (%chrome/browser-region/region.properties)
 # the following files are browser-specific overrides

--- a/browser/modules/ContentCrashHandlers.jsm
+++ b/browser/modules/ContentCrashHandlers.jsm
@@ -741,17 +741,20 @@ this.UnsubmittedCrashHandler = {
    * YYYYMMDD.
    *
    * @param someDate (Date, optional)
    *        The Date to convert to the string. If not provided,
    *        defaults to today's date.
    * @returns String
    */
   dateString(someDate = new Date()) {
-    return someDate.toLocaleFormat("%Y%m%d");
+    let year = String(someDate.getFullYear()).padStart(4, "0");
+    let month = String(someDate.getMonth() + 1).padStart(2, "0");
+    let day = String(someDate.getDate()).padStart(2, "0");
+    return year + month + day;
   },
 
   /**
    * Attempts to show a notification bar to the user in the most
    * recent browser window asking them to submit some crash report
    * IDs. If a notification cannot be shown (for example, there
    * is no browser window), this method exits silently.
    *

--- a/browser/modules/test/browser.ini
+++ b/browser/modules/test/browser.ini
@@ -32,12 +32,9 @@ support-files =
   usageTelemetrySearchSuggestions.sjs
   usageTelemetrySearchSuggestions.xml
 [browser_UsageTelemetry_searchbar.js]
 support-files =
   usageTelemetrySearchSuggestions.sjs
   usageTelemetrySearchSuggestions.xml
 [browser_UsageTelemetry_content.js]
 [browser_UsageTelemetry_content_aboutHome.js]
-# Disabled for intermittent failures.
-# Re-enabling this test is tracked in bug 1313825.
-skip-if = true
 [browser_urlBar_zoom.js]

--- a/browser/modules/test/browser_UnsubmittedCrashHandler.js
+++ b/browser/modules/test/browser_UnsubmittedCrashHandler.js
@@ -441,17 +441,17 @@ add_task(function* test_can_ignore() {
  * lastShownDate is set for today.
  */
 add_task(function* test_last_shown_date() {
   yield createPendingCrashReports(1);
   let notification =
     yield UnsubmittedCrashHandler.checkForUnsubmittedCrashReports();
   Assert.ok(notification, "There should be a notification");
 
-  let today = new Date().toLocaleFormat("%Y%m%d");
+  let today = UnsubmittedCrashHandler.dateString(new Date());
   let lastShownDate =
     UnsubmittedCrashHandler.prefs.getCharPref("lastShownDate");
   Assert.equal(today, lastShownDate,
                "Last shown date should be today.");
 
   UnsubmittedCrashHandler.prefs.clearUserPref("lastShownDate");
   gNotificationBox.removeNotification(notification, true);
   clearPendingCrashReports();
@@ -536,17 +536,17 @@ add_task(function* test_dont_decrement_c
   gNotificationBox.removeNotification(notification, true);
 
   let shutdownWhileShowing =
     UnsubmittedCrashHandler.prefs.getBoolPref("shutdownWhileShowing");
   Assert.ok(shutdownWhileShowing,
             "We should have noticed that we uninitted while showing " +
             "the notification.");
 
-  let today = new Date().toLocaleFormat("%Y%m%d");
+  let today = UnsubmittedCrashHandler.dateString(new Date());
   let lastShownDate =
     UnsubmittedCrashHandler.prefs.getCharPref("lastShownDate");
   Assert.equal(today, lastShownDate,
                "Last shown date should be today.");
 
   UnsubmittedCrashHandler.init();
 
   notification =
@@ -585,17 +585,17 @@ add_task(function* test_decrement_chance
 
   let shutdownWhileShowing =
     UnsubmittedCrashHandler.prefs.getBoolPref("shutdownWhileShowing");
   Assert.ok(shutdownWhileShowing,
             "We should have noticed that we uninitted while showing " +
             "the notification.");
 
   // Now pretend that the notification was shown yesterday.
-  let yesterday = new Date(Date.now() - DAY).toLocaleFormat("%Y%m%d");
+  let yesterday = UnsubmittedCrashHandler.dateString(new Date(Date.now() - DAY));
   UnsubmittedCrashHandler.prefs.setCharPref("lastShownDate", yesterday);
 
   UnsubmittedCrashHandler.init();
 
   notification =
     yield UnsubmittedCrashHandler.checkForUnsubmittedCrashReports();
   Assert.ok(notification, "There should still be a notification");
 
@@ -613,47 +613,47 @@ add_task(function* test_decrement_chance
 /**
  * Tests that if we've shutdown too many times showing the
  * notification, and we've run out of chances, then
  * browser.crashReports.unsubmittedCheck.suppressUntilDate is
  * set for some days into the future.
  */
 add_task(function* test_can_suppress_after_chances() {
   // Pretend that a notification was shown yesterday.
-  let yesterday = new Date(Date.now() - DAY).toLocaleFormat("%Y%m%d");
+  let yesterday = UnsubmittedCrashHandler.dateString(new Date(Date.now() - DAY));
   UnsubmittedCrashHandler.prefs.setCharPref("lastShownDate", yesterday);
   UnsubmittedCrashHandler.prefs.setBoolPref("shutdownWhileShowing", true);
   UnsubmittedCrashHandler.prefs.setIntPref("chancesUntilSuppress", 0);
 
   yield createPendingCrashReports(1);
   let notification =
     yield UnsubmittedCrashHandler.checkForUnsubmittedCrashReports();
   Assert.equal(notification, null,
                "There should be no notification if we've run out of chances");
 
   // We should have set suppressUntilDate into the future
   let suppressUntilDate =
     UnsubmittedCrashHandler.prefs.getCharPref("suppressUntilDate");
 
-  let today = new Date().toLocaleFormat("%Y%m%d");
+  let today = UnsubmittedCrashHandler.dateString(new Date());
   Assert.ok(suppressUntilDate > today,
             "We should be suppressing until some days into the future.");
 
   UnsubmittedCrashHandler.prefs.clearUserPref("chancesUntilSuppress");
   UnsubmittedCrashHandler.prefs.clearUserPref("suppressUntilDate");
   UnsubmittedCrashHandler.prefs.clearUserPref("lastShownDate");
   clearPendingCrashReports();
 });
 
 /**
  * Tests that if there's a suppression date set, then no notification
  * will be shown even if there are pending crash reports.
  */
 add_task(function* test_suppression() {
-  let future = new Date(Date.now() + (DAY * 5)).toLocaleFormat("%Y%m%d");
+  let future = UnsubmittedCrashHandler.dateString(new Date(Date.now() + (DAY * 5)));
   UnsubmittedCrashHandler.prefs.setCharPref("suppressUntilDate", future);
   UnsubmittedCrashHandler.uninit();
   UnsubmittedCrashHandler.init();
 
   Assert.ok(UnsubmittedCrashHandler.suppressed,
             "The UnsubmittedCrashHandler should be suppressed.");
   UnsubmittedCrashHandler.prefs.clearUserPref("suppressUntilDate");
 
@@ -661,17 +661,17 @@ add_task(function* test_suppression() {
   UnsubmittedCrashHandler.init();
 });
 
 /**
  * Tests that if there's a suppression date set, but we've exceeded
  * it, then we can show the notification again.
  */
 add_task(function* test_end_suppression() {
-  let yesterday = new Date(Date.now() - DAY).toLocaleFormat("%Y%m%d");
+  let yesterday = UnsubmittedCrashHandler.dateString(new Date(Date.now() - DAY));
   UnsubmittedCrashHandler.prefs.setCharPref("suppressUntilDate", yesterday);
   UnsubmittedCrashHandler.uninit();
   UnsubmittedCrashHandler.init();
 
   Assert.ok(!UnsubmittedCrashHandler.suppressed,
             "The UnsubmittedCrashHandler should not be suppressed.");
   Assert.ok(!UnsubmittedCrashHandler.prefs.prefHasUserValue("suppressUntilDate"),
             "The suppression date should been cleared from preferences.");

--- a/browser/modules/test/browser_UsageTelemetry_content_aboutHome.js
+++ b/browser/modules/test/browser_UsageTelemetry_content_aboutHome.js
@@ -34,24 +34,31 @@ add_task(function* setup() {
     Services.search.removeEngine(engineOneOff);
   });
 });
 
 add_task(function* test_abouthome_simpleQuery() {
   // Let's reset the counts.
   Services.telemetry.clearScalars();
 
-  let tab = yield BrowserTestUtils.openNewForegroundTab(gBrowser, "about:home");
-  yield new Promise(resolve => {
+  let tab = yield BrowserTestUtils.openNewForegroundTab(gBrowser);
+
+  info("Setup waiting for AboutHomeLoadSnippetsCompleted.");
+  let promiseAboutHomeLoaded = new Promise(resolve => {
     tab.linkedBrowser.addEventListener("AboutHomeLoadSnippetsCompleted", function loadListener(event) {
       tab.linkedBrowser.removeEventListener("AboutHomeLoadSnippetsCompleted", loadListener, true);
       resolve();
     }, true, true);
   });
 
+  info("Load about:home.");
+  tab.linkedBrowser.loadURI("about:home");
+  info("Wait for AboutHomeLoadSnippetsCompleted.");
+  yield promiseAboutHomeLoaded;
+
   info("Trigger a simple serch, just test + enter.");
   let p = BrowserTestUtils.browserLoaded(tab.linkedBrowser);
   yield typeInSearchField(tab.linkedBrowser, "test query", "searchText");
   yield BrowserTestUtils.synthesizeKey("VK_RETURN", {}, tab.linkedBrowser);
   yield p;
 
   // Check if the scalars contain the expected values.
   const scalars =

--- a/browser/themes/osx/devedition.css
+++ b/browser/themes/osx/devedition.css
@@ -82,21 +82,16 @@
 
 /* Use smaller back button icon */
 @media (min-resolution: 2dppx) {
   #back-button:hover:active:not([disabled="true"]) {
     -moz-image-region: rect(36px, 108px, 72px, 72px);
   }
 }
 
-#forward-button:hover:active:not(:-moz-lwtheme) {
-  background-image: none;
-  box-shadow: none;
-}
-
 /* Don't use the default background for tabs toolbar */
 #TabsToolbar {
   -moz-appearance: none !important;
 }
 
 /* Prevent the hover styling from on the identity icon from overlapping the
    urlbar border. */
 #identity-box {

--- a/browser/themes/osx/places/organizer.css
+++ b/browser/themes/osx/places/organizer.css
@@ -44,85 +44,69 @@
 }
 
 #placesList > treechildren::-moz-tree-twisty {
   -moz-appearance: none;
   padding: 0 2px;
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed");
 }
 
-#placesList > treechildren::-moz-tree-twisty(selected) {
+#placesList > treechildren::-moz-tree-twisty(closed, selected) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-inverted");
 }
 
 #placesList > treechildren::-moz-tree-twisty(open) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded");
 }
 
 #placesList > treechildren::-moz-tree-twisty(open, selected) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded-inverted");
 }
 
-#placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty {
+#placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(closed) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-rtl");
 }
 
-#placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(selected) {
+#placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(closed, selected) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-inverted-rtl");
 }
 
-#placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(open) {
-  list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded");
-}
-
-#placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(open, selected) {
-  list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded-inverted");
-}
-
 @media (-moz-mac-yosemite-theme) {
   #placesList > treechildren::-moz-tree-cell-text(selected) {
     color: -moz-dialogtext;
     font-weight: 500;
   }
 
   #placesList > treechildren::-moz-tree-cell-text(selected, focus) {
     color: #fff;
   }
 
-  #placesList > treechildren::-moz-tree-twisty(selected) {
+  #placesList > treechildren::-moz-tree-twisty(closed, selected) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed");
   }
 
-  #placesList > treechildren::-moz-tree-twisty(selected, focus) {
+  #placesList > treechildren::-moz-tree-twisty(closed, selected, focus) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-inverted");
   }
 
   #placesList > treechildren::-moz-tree-twisty(open, selected) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded");
   }
 
   #placesList > treechildren::-moz-tree-twisty(open, selected, focus) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded-inverted");
   }
 
-  #placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(selected) {
+  #placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(closed, selected) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-rtl");
   }
 
-  #placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(selected, focus) {
+  #placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(closed, selected, focus) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-inverted-rtl");
   }
-
-  #placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(open, selected) {
-    list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded");
-  }
-
-  #placesList > treechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(open, selected, focus) {
-    list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded-inverted");
-  }
 }
 
 #placesToolbar {
   padding: 0 4px 3px;
 }
 
 #placesView {
   border-top: none !important;

--- a/browser/themes/osx/places/places.css
+++ b/browser/themes/osx/places/places.css
@@ -62,85 +62,69 @@
 }
 
 .sidebar-placesTreechildren::-moz-tree-twisty {
   -moz-appearance: none;
   padding: 0 2px;
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed");
 }
 
-.sidebar-placesTreechildren::-moz-tree-twisty(selected) {
+.sidebar-placesTreechildren::-moz-tree-twisty(closed, selected) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-inverted");
 }
 
 .sidebar-placesTreechildren::-moz-tree-twisty(open) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded");
 }
 
 .sidebar-placesTreechildren::-moz-tree-twisty(open, selected) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded-inverted");
 }
 
-.sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty {
+.sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(closed) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-rtl");
 }
 
-.sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(selected) {
+.sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(closed, selected) {
   list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-inverted-rtl");
 }
 
-.sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(open) {
-  list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded");
-}
-
-.sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(open, selected) {
-  list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded-inverted");
-}
-
 @media (-moz-mac-yosemite-theme) {
   .sidebar-placesTreechildren::-moz-tree-cell-text(selected) {
     color: -moz-dialogtext;
     font-weight: 500;
   }
 
   .sidebar-placesTreechildren::-moz-tree-cell-text(selected, focus) {
     color: #fff;
   }
 
-  .sidebar-placesTreechildren::-moz-tree-twisty(selected) {
+  .sidebar-placesTreechildren::-moz-tree-twisty(closed, selected) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed");
   }
 
-  .sidebar-placesTreechildren::-moz-tree-twisty(selected, focus) {
+  .sidebar-placesTreechildren::-moz-tree-twisty(closed, selected, focus) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-inverted");
   }
 
   .sidebar-placesTreechildren::-moz-tree-twisty(open, selected) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded");
   }
 
   .sidebar-placesTreechildren::-moz-tree-twisty(open, selected, focus) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded-inverted");
   }
 
-  .sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(selected) {
+  .sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(closed, selected) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-rtl");
   }
 
-  .sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(selected, focus) {
+  .sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(closed, selected, focus) {
     list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-collapsed-inverted-rtl")
   }
-
-  .sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(open, selected) {
-    list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded");
-  }
-
-  .sidebar-placesTreechildren:-moz-locale-dir(rtl)::-moz-tree-twisty(open, selected, focus) {
-    list-style-image: url("chrome://global/skin/tree/arrow-disclosure.svg#arrow-disclosure-expanded-inverted");
-  }
 }
 
 #viewButton {
   -moz-appearance: none;
   padding-bottom: 1px;
   padding-inline-start: 5px;
   padding-inline-end: 0px;
   margin: 0;

--- a/browser/themes/shared/devedition.inc.css
+++ b/browser/themes/shared/devedition.inc.css
@@ -179,17 +179,16 @@
 /* Using toolbar[brighttext] instead of important to override linux */
 toolbar[brighttext] #downloads-indicator-counter {
   text-shadow: var(--toolbarbutton-text-shadow);
   color: var(--chrome-color);
 }
 
 #TabsToolbar {
   text-shadow: none !important;
-  color: var(--chrome-color) !important; /* Make sure that the brighttext attribute is added */
 }
 
 /* URL bar and search bar*/
 #urlbar,
 #navigator-toolbox .searchbar-textbox {
   background-color: var(--url-and-searchbar-background-color) !important;
   background-image: none !important;
   color: inherit !important;

--- a/build/gyp.mozbuild
+++ b/build/gyp.mozbuild
@@ -104,16 +104,17 @@ flavors = {
     'NetBSD': 'netbsd',
     'OpenBSD': 'openbsd',
 }
 gyp_vars['OS'] = flavors.get(os)
 
 arches = {
     'x86_64': 'x64',
     'x86': 'ia32',
+    'aarch64': 'arm64',
 }
 
 gyp_vars['target_arch'] = arches.get(CONFIG['CPU_ARCH'], CONFIG['CPU_ARCH'])
 
 if CONFIG['ARM_ARCH']:
     if int(CONFIG['ARM_ARCH']) < 7:
         gyp_vars['armv7'] = 0
         gyp_vars['arm_neon_optional'] = 0

--- a/caps/BasePrincipal.cpp
+++ b/caps/BasePrincipal.cpp
@@ -18,16 +18,17 @@
 
 #include "nsPrincipal.h"
 #include "nsNetUtil.h"
 #include "nsIURIWithPrincipal.h"
 #include "nsNullPrincipal.h"
 #include "nsScriptSecurityManager.h"
 #include "nsServiceManagerUtils.h"
 
+#include "mozilla/dom/ChromeUtils.h"
 #include "mozilla/dom/CSPDictionariesBinding.h"
 #include "mozilla/dom/quota/QuotaManager.h"
 #include "mozilla/dom/ToJSValue.h"
 #include "mozilla/dom/URLSearchParams.h"
 
 namespace mozilla {
 
 using dom::URLParams;
@@ -390,16 +391,26 @@ BasePrincipal::GetOriginNoSuffix(nsACStr
 {
   return GetOriginInternal(aOrigin);
 }
 
 bool
 BasePrincipal::Subsumes(nsIPrincipal* aOther, DocumentDomainConsideration aConsideration)
 {
   MOZ_ASSERT(aOther);
+
+  // Expanded principals handle origin attributes for each of their
+  // sub-principals individually, null principals do only simple checks for
+  // pointer equality, and system principals are immune to origin attributes
+  // checks, so only do this check for codebase principals.
+  if (Kind() == eCodebasePrincipal &&
+      OriginAttributesRef() != Cast(aOther)->OriginAttributesRef()) {
+    return false;
+  }
+
   return SubsumesInternal(aOther, aConsideration);
 }
 
 NS_IMETHODIMP
 BasePrincipal::Equals(nsIPrincipal *aOther, bool *aResult)
 {
   NS_ENSURE_TRUE(aOther, NS_ERROR_INVALID_ARG);
   *aResult = Subsumes(aOther, DontConsiderDocumentDomain) &&
@@ -411,16 +422,32 @@ NS_IMETHODIMP
 BasePrincipal::EqualsConsideringDomain(nsIPrincipal *aOther, bool *aResult)
 {
   NS_ENSURE_TRUE(aOther, NS_ERROR_INVALID_ARG);
   *aResult = Subsumes(aOther, ConsiderDocumentDomain) &&
              Cast(aOther)->Subsumes(this, ConsiderDocumentDomain);
   return NS_OK;
 }
 
+bool
+BasePrincipal::EqualsIgnoringAddonId(nsIPrincipal *aOther)
+{
+  MOZ_ASSERT(aOther);
+
+  // Note that this will not work for expanded principals, nor is it intended
+  // to.
+  if (!dom::ChromeUtils::IsOriginAttributesEqualIgnoringAddonId(
+          OriginAttributesRef(), Cast(aOther)->OriginAttributesRef())) {
+    return false;
+  }
+
+  return SubsumesInternal(aOther, DontConsiderDocumentDomain) &&
+         Cast(aOther)->SubsumesInternal(this, DontConsiderDocumentDomain);
+}
+
 NS_IMETHODIMP
 BasePrincipal::Subsumes(nsIPrincipal *aOther, bool *aResult)
 {
   NS_ENSURE_TRUE(aOther, NS_ERROR_INVALID_ARG);
   *aResult = Subsumes(aOther, DontConsiderDocumentDomain);
   return NS_OK;
 }
 

--- a/caps/BasePrincipal.h
+++ b/caps/BasePrincipal.h
@@ -284,16 +284,18 @@ public:
   NS_IMETHOD GetAppStatus(uint16_t* aAppStatus) final;
   NS_IMETHOD GetAppId(uint32_t* aAppStatus) final;
   NS_IMETHOD GetAddonId(nsAString& aAddonId) final;
   NS_IMETHOD GetIsInIsolatedMozBrowserElement(bool* aIsInIsolatedMozBrowserElement) final;
   NS_IMETHOD GetUnknownAppId(bool* aUnknownAppId) final;
   NS_IMETHOD GetUserContextId(uint32_t* aUserContextId) final;
   NS_IMETHOD GetPrivateBrowsingId(uint32_t* aPrivateBrowsingId) final;
 
+  bool EqualsIgnoringAddonId(nsIPrincipal *aOther);
+
   virtual bool AddonHasPermission(const nsAString& aPerm);
 
   virtual bool IsOnCSSUnprefixingWhitelist() override { return false; }
 
   virtual bool IsCodebasePrincipal() const { return false; };
 
   static BasePrincipal* Cast(nsIPrincipal* aPrin) { return static_cast<BasePrincipal*>(aPrin); }
   static already_AddRefed<BasePrincipal>
@@ -316,16 +318,18 @@ public:
   virtual PrincipalKind Kind() = 0;
 
   already_AddRefed<BasePrincipal> CloneStrippingUserContextIdAndFirstPartyDomain();
 
 protected:
   virtual ~BasePrincipal();
 
   virtual nsresult GetOriginInternal(nsACString& aOrigin) = 0;
+  // Note that this does not check OriginAttributes. Callers that depend on
+  // those must call Subsumes instead.
   virtual bool SubsumesInternal(nsIPrincipal* aOther, DocumentDomainConsideration aConsider) = 0;
 
   // Internal, side-effect-free check to determine whether the concrete
   // principal would allow the load ignoring any common behavior implemented in
   // BasePrincipal::CheckMayLoad.
   virtual bool MayLoadInternal(nsIURI* aURI) = 0;
   friend class ::nsExpandedPrincipal;
 

--- a/caps/nsPrincipal.cpp
+++ b/caps/nsPrincipal.cpp
@@ -192,20 +192,16 @@ nsPrincipal::SubsumesInternal(nsIPrincip
 {
   MOZ_ASSERT(aOther);
 
   // For nsPrincipal, Subsumes is equivalent to Equals.
   if (aOther == this) {
     return true;
   }
 
-  if (OriginAttributesRef() != Cast(aOther)->OriginAttributesRef()) {
-    return false;
-  }
-
   // If either the subject or the object has changed its principal by
   // explicitly setting document.domain then the other must also have
   // done so in order to be considered the same origin. This prevents
   // DNS spoofing based on document.domain (154930)
   nsresult rv;
   if (aConsideration == ConsiderDocumentDomain) {
     // Get .domain on each principal.
     nsCOMPtr<nsIURI> thisDomain, otherDomain;
@@ -726,16 +722,19 @@ nsExpandedPrincipal::SubsumesInternal(ns
 {
   // If aOther is an ExpandedPrincipal too, we break it down into its component
   // nsIPrincipals, and check subsumes on each one.
   nsCOMPtr<nsIExpandedPrincipal> expanded = do_QueryInterface(aOther);
   if (expanded) {
     nsTArray< nsCOMPtr<nsIPrincipal> >* otherList;
     expanded->GetWhiteList(&otherList);
     for (uint32_t i = 0; i < otherList->Length(); ++i){
+      // Use SubsumesInternal rather than Subsumes here, since OriginAttribute
+      // checks are only done between non-expanded sub-principals, and we don't
+      // need to incur the extra virtual call overhead.
       if (!SubsumesInternal((*otherList)[i], aConsideration)) {
         return false;
       }
     }
     return true;
   }
 
   // We're dealing with a regular principal. One of our principals must subsume

--- a/devtools/client/inspector/components/box-model.js
+++ b/devtools/client/inspector/components/box-model.js
@@ -4,17 +4,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 const {Task} = require("devtools/shared/task");
 const {InplaceEditor, editableItem} =
       require("devtools/client/shared/inplace-editor");
-const {ReflowFront} = require("devtools/shared/fronts/layout");
+const {ReflowFront} = require("devtools/shared/fronts/reflow");
 const {LocalizationHelper} = require("devtools/shared/l10n");
 const {getCssProperties} = require("devtools/shared/fronts/css-properties");
 
 const STRINGS_URI = "devtools/locale/shared.properties";
 const STRINGS_INSPECTOR = "devtools-shared/locale/styleinspector.properties";
 const SHARED_L10N = new LocalizationHelper(STRINGS_URI);
 const INSPECTOR_L10N = new LocalizationHelper(STRINGS_INSPECTOR);
 const NUMERIC = /^-?[\d\.]+$/;

--- a/devtools/client/shared/view-source.js
+++ b/devtools/client/shared/view-source.js
@@ -50,46 +50,52 @@ exports.viewSourceInStyleEditor = Task.a
  *
  * @return {Promise<boolean>}
  */
 exports.viewSourceInDebugger = Task.async(function* (toolbox, sourceURL, sourceLine) {
   // If the Debugger was already open, switch to it and try to show the
   // source immediately. Otherwise, initialize it and wait for the sources
   // to be added first.
   let debuggerAlreadyOpen = toolbox.getPanel("jsdebugger");
-  let { panelWin: dbg } = yield toolbox.loadTool("jsdebugger");
+  let dbg = yield toolbox.loadTool("jsdebugger");
 
   // New debugger frontend
   if (Services.prefs.getBoolPref("devtools.debugger.new-debugger-frontend")) {
     yield toolbox.selectTool("jsdebugger");
-    // TODO: Properly handle case where source will never exist in the
-    // debugger
-    dbg.actions.selectSourceURL(sourceURL, { line: sourceLine });
-    return true;
+    const source = dbg._selectors().getSourceByURL(dbg._getState(), sourceURL);
+    if (source) {
+      dbg._actions().selectSourceByURL(sourceURL, { line: sourceLine });
+      return true;
+    }
+
+    exports.viewSource(toolbox, sourceURL, sourceLine);
+    return false;
   }
 
+  const win = dbg.panelWin;
+
   // Old debugger frontend
   if (!debuggerAlreadyOpen) {
-    yield dbg.DebuggerController.waitForSourcesLoaded();
+    yield win.DebuggerController.waitForSourcesLoaded();
   }
 
-  let { DebuggerView } = dbg;
+  let { DebuggerView } = win;
   let { Sources } = DebuggerView;
 
   let item = Sources.getItemForAttachment(a => a.source.url === sourceURL);
   if (item) {
     yield toolbox.selectTool("jsdebugger");
 
     // Determine if the source has already finished loading. There's two cases
     // in which we need to wait for the source to be shown:
     // 1) The requested source is not yet selected and will be shown once it is
     //    selected and loaded
     // 2) The requested source is selected BUT the source text is still loading.
     const { actor } = item.attachment.source;
-    const state = dbg.DebuggerController.getState();
+    const state = win.DebuggerController.getState();
 
     // (1) Is the source selected?
     const selected = state.sources.selectedSource;
     const isSelected = selected === actor;
 
     // (2) Has the source text finished loading?
     let isLoading = false;
 
@@ -101,17 +107,17 @@ exports.viewSourceInDebugger = Task.asyn
       isLoading = sourceTextInfo && sourceTextInfo.loading;
     }
 
     // Select the requested source
     DebuggerView.setEditorLocation(actor, sourceLine, { noDebug: true });
 
     // Wait for it to load
     if (!isSelected || isLoading) {
-      yield dbg.DebuggerController.waitForSourceShown(sourceURL);
+      yield win.DebuggerController.waitForSourceShown(sourceURL);
     }
     return true;
   }
 
   // If not found, still attempt to open in View Source
   exports.viewSource(toolbox, sourceURL, sourceLine);
   return false;
 });

--- a/devtools/client/webconsole/test/browser_webconsole_bug_646025_console_file_location.js
+++ b/devtools/client/webconsole/test/browser_webconsole_bug_646025_console_file_location.js
@@ -22,36 +22,36 @@ add_task(function* () {
   BrowserTestUtils.loadURI(gBrowser.selectedBrowser, TEST_URI2);
 
   yield waitForMessages({
     webconsole: hud,
     messages: [{
       text: "message for level log",
       category: CATEGORY_WEBDEV,
       severity: SEVERITY_LOG,
-      source: { url: "test-file-location.js", line: 6 },
+      source: { url: "test-file-location.js", line: 8 },
     },
     {
       text: "message for level info",
       category: CATEGORY_WEBDEV,
       severity: SEVERITY_INFO,
-      source: { url: "test-file-location.js", line: 7 },
+      source: { url: "test-file-location.js", line: 9 },
     },
     {
       text: "message for level warn",
       category: CATEGORY_WEBDEV,
       severity: SEVERITY_WARNING,
-      source: { url: "test-file-location.js", line: 8 },
+      source: { url: "test-file-location.js", line: 10 },
     },
     {
       text: "message for level error",
       category: CATEGORY_WEBDEV,
       severity: SEVERITY_ERROR,
-      source: { url: "test-file-location.js", line: 9 },
+      source: { url: "test-file-location.js", line: 11 },
     },
     {
       text: "message for level debug",
       category: CATEGORY_WEBDEV,
       severity: SEVERITY_LOG,
-      source: { url: "test-file-location.js", line: 10 },
+      source: { url: "test-file-location.js", line: 12 },
     }],
   });
 });

--- a/devtools/client/webconsole/test/browser_webconsole_dont_navigate_on_doubleclick.js
+++ b/devtools/client/webconsole/test/browser_webconsole_dont_navigate_on_doubleclick.js
@@ -36,19 +36,19 @@ function test() {
         category: CATEGORY_NETWORK
       }]
     });
 
     let networkEventMessage = messages[0].matched.values().next().value;
     let urlNode = networkEventMessage.querySelector(".url");
 
     let deferred = promise.defer();
-    urlNode.addEventListener("click", function onClick(aEvent) {
+    urlNode.addEventListener("click", function onClick(event) {
       urlNode.removeEventListener("click", onClick);
-      ok(aEvent.defaultPrevented, "The default action was prevented.");
+      ok(event.defaultPrevented, "The default action was prevented.");
 
       deferred.resolve();
     });
 
     EventUtils.synthesizeMouseAtCenter(urlNode, {clickCount: 2},
                                        hud.iframeWindow);
 
     yield deferred.promise;

--- a/devtools/client/webconsole/test/browser_webconsole_view_source.js
+++ b/devtools/client/webconsole/test/browser_webconsole_view_source.js
@@ -8,23 +8,27 @@
 // have their locations opened in Debugger, we need to test a security message in
 // order to have it opened in the standard View Source window.
 
 "use strict";
 
 const TEST_URI = "https://example.com/browser/devtools/client/webconsole/" +
                  "test/test-mixedcontent-securityerrors.html";
 
-// Force the old debugger UI since it's directly used (see Bug 1301705)
-Services.prefs.setBoolPref("devtools.debugger.new-debugger-frontend", false);
-registerCleanupFunction(function* () {
+add_task(function* () {
+  yield actuallyTest();
+});
+
+add_task(function* () {
+  Services.prefs.setBoolPref("devtools.debugger.new-debugger-frontend", false);
+  yield actuallyTest();
   Services.prefs.clearUserPref("devtools.debugger.new-debugger-frontend");
 });
 
-add_task(function* () {
+var actuallyTest = Task.async(function*() {
   yield loadTab(TEST_URI);
   let hud = yield openConsole(null);
   info("console opened");
 
   let [result] = yield waitForMessages({
     webconsole: hud,
     messages: [{
       text: "Blocked loading mixed active content",

--- a/devtools/client/webconsole/test/test-file-location.js
+++ b/devtools/client/webconsole/test/test-file-location.js
@@ -1,10 +1,12 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
+"use strict";
+
 console.log("message for level log");
 console.info("message for level info");
 console.warn("message for level warn");
 console.error("message for level error");
 console.debug("message for level debug");

--- a/devtools/server/actors/inspector.js
+++ b/devtools/server/actors/inspector.js
@@ -68,17 +68,17 @@ const {
 const {EyeDropper} = require("devtools/server/actors/highlighters/eye-dropper");
 const {
   isAnonymous,
   isNativeAnonymous,
   isXBLAnonymous,
   isShadowAnonymous,
   getFrameElement
 } = require("devtools/shared/layout/utils");
-const {getLayoutChangesObserver, releaseLayoutChangesObserver} = require("devtools/server/actors/layout");
+const {getLayoutChangesObserver, releaseLayoutChangesObserver} = require("devtools/server/actors/reflow");
 const nodeFilterConstants = require("devtools/shared/dom-node-filter-constants");
 
 const {EventParsers} = require("devtools/server/event-parsers");
 const {nodeSpec, nodeListSpec, walkerSpec, inspectorSpec} = require("devtools/shared/specs/inspector");
 
 const FONT_FAMILY_PREVIEW_TEXT = "The quick brown fox jumps over the lazy dog";
 const FONT_FAMILY_PREVIEW_TEXT_SIZE = 20;
 const PSEUDO_CLASSES = [":hover", ":active", ":focus"];

--- a/devtools/server/actors/moz.build
+++ b/devtools/server/actors/moz.build
@@ -32,28 +32,28 @@ DevToolsModules(
     'eventlooplag.js',
     'frame.js',
     'framerate.js',
     'gcli.js',
     'heap-snapshot-file.js',
     'highlighters.css',
     'highlighters.js',
     'inspector.js',
-    'layout.js',
     'memory.js',
     'monitor.js',
     'object.js',
     'performance-entries.js',
     'performance-recording.js',
     'performance.js',
     'preference.js',
     'pretty-print-worker.js',
     'process.js',
     'profiler.js',
     'promises.js',
+    'reflow.js',
     'root.js',
     'script.js',
     'settings.js',
     'source.js',
     'storage.js',
     'string.js',
     'styleeditor.js',
     'styles.js',

rename from devtools/server/actors/layout.js
rename to devtools/server/actors/reflow.js
--- a/devtools/server/actors/layout.js
+++ b/devtools/server/actors/reflow.js
@@ -26,17 +26,17 @@
 
 const {Ci} = require("chrome");
 const {XPCOMUtils} = require("resource://gre/modules/XPCOMUtils.jsm");
 const protocol = require("devtools/shared/protocol");
 const {method, Arg} = protocol;
 const events = require("sdk/event/core");
 const Heritage = require("sdk/core/heritage");
 const EventEmitter = require("devtools/shared/event-emitter");
-const {reflowSpec} = require("devtools/shared/specs/layout");
+const {reflowSpec} = require("devtools/shared/specs/reflow");
 
 /**
  * The reflow actor tracks reflows and emits events about them.
  */
 var ReflowActor = exports.ReflowActor = protocol.ActorClassWithSpec(reflowSpec, {
   initialize: function (conn, tabActor) {
     protocol.Actor.prototype.initialize.call(this, conn);
 

--- a/devtools/server/main.js
+++ b/devtools/server/main.js
@@ -502,17 +502,17 @@ var DebuggerServer = {
       constructor: "FramerateActor",
       type: { tab: true }
     });
     this.registerModule("devtools/server/actors/eventlooplag", {
       prefix: "eventLoopLag",
       constructor: "EventLoopLagActor",
       type: { tab: true }
     });
-    this.registerModule("devtools/server/actors/layout", {
+    this.registerModule("devtools/server/actors/reflow", {
       prefix: "reflow",
       constructor: "ReflowActor",
       type: { tab: true }
     });
     this.registerModule("devtools/server/actors/css-properties", {
       prefix: "cssProperties",
       constructor: "CssPropertiesActor",
       type: { tab: true }

--- a/devtools/server/tests/unit/test_layout-reflows-observer.js
+++ b/devtools/server/tests/unit/test_layout-reflows-observer.js
@@ -2,17 +2,17 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // Test the LayoutChangesObserver
 
 var {
   getLayoutChangesObserver,
   releaseLayoutChangesObserver,
   LayoutChangesObserver
-} = require("devtools/server/actors/layout");
+} = require("devtools/server/actors/reflow");
 
 // Override set/clearTimeout on LayoutChangesObserver to avoid depending on
 // time in this unit test. This means that LayoutChangesObserver.eventLoopTimer
 // will be the timeout callback instead of the timeout itself, so test cases
 // will need to execute it to fake a timeout
 LayoutChangesObserver.prototype._setTimeout = cb => cb;
 LayoutChangesObserver.prototype._clearTimeout = function () {};
 

--- a/devtools/shared/fronts/moz.build
+++ b/devtools/shared/fronts/moz.build
@@ -16,24 +16,24 @@ DevToolsModules(
     'director-manager.js',
     'director-registry.js',
     'emulation.js',
     'eventlooplag.js',
     'framerate.js',
     'gcli.js',
     'highlighters.js',
     'inspector.js',
-    'layout.js',
     'memory.js',
     'performance-entries.js',
     'performance-recording.js',
     'performance.js',
     'preference.js',
     'profiler.js',
     'promises.js',
+    'reflow.js',
     'settings.js',
     'storage.js',
     'string.js',
     'styles.js',
     'stylesheets.js',
     'timeline.js',
     'webaudio.js',
     'webgl.js'

rename from devtools/shared/fronts/layout.js
rename to devtools/shared/fronts/reflow.js
--- a/devtools/shared/fronts/layout.js
+++ b/devtools/shared/fronts/reflow.js
@@ -1,14 +1,15 @@
 /* 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/. */
+
 "use strict";
 
-const {reflowSpec} = require("devtools/shared/specs/layout");
+const {reflowSpec} = require("devtools/shared/specs/reflow");
 const protocol = require("devtools/shared/protocol");
 
 /**
  * Usage example of the reflow front:
  *
  * let front = ReflowFront(toolbox.target.client, toolbox.target.form);
  * front.on("reflows", this._onReflows);
  * front.start();

--- a/devtools/shared/layout/utils.js
+++ b/devtools/shared/layout/utils.js
@@ -2,17 +2,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 const { Ci, Cc } = require("chrome");
 const nodeFilterConstants = require("devtools/shared/dom-node-filter-constants");
 
-loader.lazyRequireGetter(this, "setIgnoreLayoutChanges", "devtools/server/actors/layout", true);
+loader.lazyRequireGetter(this, "setIgnoreLayoutChanges", "devtools/server/actors/reflow", true);
 exports.setIgnoreLayoutChanges = (...args) =>
   this.setIgnoreLayoutChanges(...args);
 
 /**
  * Returns the `DOMWindowUtils` for the window given.
  *
  * @param {DOMWindow} win
  * @returns {DOMWindowUtils}

--- a/devtools/shared/specs/moz.build
+++ b/devtools/shared/specs/moz.build
@@ -20,25 +20,25 @@ DevToolsModules(
     'environment.js',
     'eventlooplag.js',
     'frame.js',
     'framerate.js',
     'gcli.js',
     'heap-snapshot-file.js',
     'highlighters.js',
     'inspector.js',
-    'layout.js',
     'memory.js',
     'node.js',
     'performance-entries.js',
     'performance-recording.js',
     'performance.js',
     'preference.js',
     'profiler.js',
     'promises.js',
+    'reflow.js',
     'script.js',
     'settings.js',
     'source.js',
     'storage.js',
     'string.js',
     'styleeditor.js',
     'styles.js',
     'stylesheets.js',

rename from devtools/shared/specs/layout.js
rename to devtools/shared/specs/reflow.js
--- a/devtools/shared/specs/layout.js
+++ b/devtools/shared/specs/reflow.js
@@ -1,11 +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/. */
+
 "use strict";
 
 const {Arg, generateActorSpec} = require("devtools/shared/protocol");
 
 const reflowSpec = generateActorSpec({
   typeName: "reflow",
 
   events: {

--- a/dom/base/File.cpp
+++ b/dom/base/File.cpp
@@ -12,17 +12,16 @@
 #include "nsContentUtils.h"
 #include "nsError.h"
 #include "nsICharsetDetector.h"
 #include "nsIConverterInputStream.h"
 #include "nsIDocument.h"
 #include "nsIFileStreams.h"
 #include "nsIInputStream.h"
 #include "nsIIPCSerializableInputStream.h"
-#include "nsIMemoryReporter.h"
 #include "nsIMIMEService.h"
 #include "nsISeekableStream.h"
 #include "nsIUnicharInputStream.h"
 #include "nsIUnicodeDecoder.h"
 #include "nsIRemoteBlob.h"
 #include "nsNetCID.h"
 #include "nsNetUtil.h"
 #include "nsIUUIDGenerator.h"
@@ -187,18 +186,18 @@ Blob::Create(nsISupports* aParent, const
   MOZ_ASSERT(!blob->mImpl->IsFile());
   return blob.forget();
 }
 
 /* static */ already_AddRefed<Blob>
 Blob::CreateStringBlob(nsISupports* aParent, const nsACString& aData,
                        const nsAString& aContentType)
 {
-  RefPtr<Blob> blob = Blob::Create(aParent,
-    new BlobImplString(aData, aContentType));
+  RefPtr<BlobImpl> blobImpl = BlobImplString::Create(aData, aContentType);
+  RefPtr<Blob> blob = Blob::Create(aParent, blobImpl);
   MOZ_ASSERT(!blob->mImpl->IsFile());
   return blob.forget();
 }
 
 /* static */ already_AddRefed<Blob>
 Blob::CreateMemoryBlob(nsISupports* aParent, void* aMemoryBuffer,
                        uint64_t aLength, const nsAString& aContentType)
 {
@@ -1046,17 +1045,37 @@ EmptyBlobImpl::GetInternalStream(nsIInpu
     aRv.Throw(rv);
     return;
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////
 // BlobImplString implementation
 
-NS_IMPL_ISUPPORTS_INHERITED0(BlobImplString, BlobImpl)
+NS_IMPL_ISUPPORTS_INHERITED(BlobImplString, BlobImpl, nsIMemoryReporter)
+
+/* static */ already_AddRefed<BlobImplString>
+BlobImplString::Create(const nsACString& aData, const nsAString& aContentType)
+{
+  RefPtr<BlobImplString> blobImpl = new BlobImplString(aData, aContentType);
+  RegisterWeakMemoryReporter(blobImpl);
+  return blobImpl.forget();
+}
+
+BlobImplString::BlobImplString(const nsACString& aData,
+                               const nsAString& aContentType)
+  : BlobImplBase(aContentType, aData.Length())
+  , mData(aData)
+{
+}
+
+BlobImplString::~BlobImplString()
+{
+  UnregisterWeakMemoryReporter(this);
+}
 
 already_AddRefed<BlobImpl>
 BlobImplString::CreateSlice(uint64_t aStart, uint64_t aLength,
                             const nsAString& aContentType,
                             ErrorResult& aRv)
 {
   RefPtr<BlobImpl> impl =
     new BlobImplString(Substring(mData, aStart, aLength),
@@ -1065,16 +1084,27 @@ BlobImplString::CreateSlice(uint64_t aSt
 }
 
 void
 BlobImplString::GetInternalStream(nsIInputStream** aStream, ErrorResult& aRv)
 {
   aRv = NS_NewCStringInputStream(aStream, mData);
 }
 
+NS_IMETHODIMP
+BlobImplString::CollectReports(nsIHandleReportCallback* aHandleReport,
+                               nsISupports* aData, bool aAnonymize)
+{
+  MOZ_COLLECT_REPORT(
+    "explicit/dom/memory-file-data/string", KIND_HEAP, UNITS_BYTES,
+    mData.SizeOfExcludingThisIfUnshared(MallocSizeOf),
+    "Memory used to back a File/Blob based on a string.");
+  return NS_OK;
+}
+
 ////////////////////////////////////////////////////////////////////////////
 // BlobImplMemory implementation
 
 NS_IMPL_ISUPPORTS_INHERITED0(BlobImplMemory, BlobImpl)
 
 already_AddRefed<BlobImpl>
 BlobImplMemory::CreateSlice(uint64_t aStart, uint64_t aLength,
                             const nsAString& aContentType,

--- a/dom/base/File.h
+++ b/dom/base/File.h
@@ -14,16 +14,17 @@
 #include "mozilla/StaticMutex.h"
 #include "mozilla/StaticPtr.h"
 #include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/dom/Date.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsCOMPtr.h"
 #include "nsIDOMBlob.h"
 #include "nsIFile.h"
+#include "nsIMemoryReporter.h"
 #include "nsIMutable.h"
 #include "nsIXMLHttpRequest.h"
 #include "nsString.h"
 #include "nsTemporaryFileInputStream.h"
 #include "nsWrapperCache.h"
 #include "nsWeakReference.h"
 
 class nsIFile;
@@ -520,37 +521,42 @@ protected:
   uint64_t mLength;
 
   int64_t mLastModificationDate;
 
   const uint64_t mSerialNumber;
 };
 
 class BlobImplString final : public BlobImplBase
+                           , public nsIMemoryReporter
 {
+  MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)
+
 public:
   NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIMEMORYREPORTER
 
-  BlobImplString(const nsACString& aData, const nsAString& aContentType)
-    : BlobImplBase(aContentType, aData.Length())
-    , mData(aData)
-  {}
+  static already_AddRefed<BlobImplString>
+  Create(const nsACString& aData, const nsAString& aContentType);
 
   virtual void GetInternalStream(nsIInputStream** aStream,
                                  ErrorResult& aRv) override;
 
   virtual already_AddRefed<BlobImpl>
   CreateSlice(uint64_t aStart, uint64_t aLength,
               const nsAString& aContentType, ErrorResult& aRv) override;
 
 private:
-  ~BlobImplString() {}
+  BlobImplString(const nsACString& aData, const nsAString& aContentType);
+
+  ~BlobImplString();
 
   nsCString mData;
 };
+
 /**
  * This class may be used off the main thread, and in particular, its
  * constructor and destructor may not run on the same thread.  Be careful!
  */
 class BlobImplMemory final : public BlobImplBase
 {
 public:
   NS_DECL_ISUPPORTS_INHERITED

--- a/dom/base/PostMessageEvent.cpp
+++ b/dom/base/PostMessageEvent.cpp
@@ -102,23 +102,29 @@ PostMessageEvent::Run()
     if (NS_WARN_IF(!targetPrin))
       return NS_OK;
 
     // Note: This is contrary to the spec with respect to file: URLs, which
     //       the spec groups into a single origin, but given we intentionally
     //       don't do that in other places it seems better to hold the line for
     //       now.  Long-term, we want HTML5 to address this so that we can
     //       be compliant while being safer.
-    if (!targetPrin->Equals(mProvidedPrincipal)) {
+    if (!BasePrincipal::Cast(targetPrin)->EqualsIgnoringAddonId(mProvidedPrincipal)) {
       nsAutoString providedOrigin, targetOrigin;
       nsresult rv = nsContentUtils::GetUTFOrigin(targetPrin, targetOrigin);
       NS_ENSURE_SUCCESS(rv, rv);
       rv = nsContentUtils::GetUTFOrigin(mProvidedPrincipal, providedOrigin);
       NS_ENSURE_SUCCESS(rv, rv);
 
+      MOZ_DIAGNOSTIC_ASSERT(providedOrigin != targetOrigin ||
+                            (BasePrincipal::Cast(mProvidedPrincipal)->OriginAttributesRef() ==
+                              BasePrincipal::Cast(targetPrin)->OriginAttributesRef()),
+                            "Unexpected postMessage call to a window with mismatched "
+                            "origin attributes");
+
       const char16_t* params[] = { providedOrigin.get(), targetOrigin.get() };
 
       nsContentUtils::ReportToConsole(nsIScriptError::errorFlag,
         NS_LITERAL_CSTRING("DOM Window"), sourceDocument,
         nsContentUtils::eDOM_PROPERTIES,
         "TargetPrincipalDoesNotMatch",
         params, ArrayLength(params));
 

--- a/dom/base/nsFocusManager.cpp
+++ b/dom/base/nsFocusManager.cpp
@@ -2016,44 +2016,112 @@ public:
   nsCOMPtr<nsISupports>   mTarget;
   RefPtr<nsPresContext> mContext;
   EventMessage            mEventMessage;
   bool                    mWindowRaised;
   bool                    mIsRefocus;
   nsCOMPtr<EventTarget>   mRelatedTarget;
 };
 
+class FocusInOutEvent : public Runnable
+{
+public:
+  FocusInOutEvent(nsISupports* aTarget, EventMessage aEventMessage,
+                 nsPresContext* aContext,
+                 nsPIDOMWindowOuter* aOriginalFocusedWindow,
+                 nsIContent* aOriginalFocusedContent,
+                 EventTarget* aRelatedTarget)
+    : mTarget(aTarget)
+    , mContext(aContext)
+    , mEventMessage(aEventMessage)
+    , mOriginalFocusedWindow(aOriginalFocusedWindow)
+    , mOriginalFocusedContent(aOriginalFocusedContent)
+    , mRelatedTarget(aRelatedTarget)
+  {
+  }
+
+  NS_IMETHOD Run() override
+  {
+    nsCOMPtr<nsIContent> originalWindowFocus = mOriginalFocusedWindow ?
+        mOriginalFocusedWindow->GetFocusedNode() :
+        nullptr;
+    // Blink does not check that focus is the same after blur, but WebKit does.
+    // Opt to follow Blink's behavior (see bug 687787).
+    if (mEventMessage == eFocusOut ||
+        originalWindowFocus == mOriginalFocusedContent) {
+      InternalFocusEvent event(true, mEventMessage);
+      event.mFlags.mBubbles = true;
+      event.mFlags.mCancelable = false;
+      event.mRelatedTarget = mRelatedTarget;
+      return EventDispatcher::Dispatch(mTarget, mContext, &event);
+    }
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsISupports>        mTarget;
+  RefPtr<nsPresContext>        mContext;
+  EventMessage                 mEventMessage;
+  nsCOMPtr<nsPIDOMWindowOuter> mOriginalFocusedWindow;
+  nsCOMPtr<nsIContent>         mOriginalFocusedContent;
+  nsCOMPtr<EventTarget>        mRelatedTarget;
+};
+
 static nsIDocument*
 GetDocumentHelper(EventTarget* aTarget)
 {
   nsCOMPtr<nsINode> node = do_QueryInterface(aTarget);
   if (!node) {
     nsCOMPtr<nsPIDOMWindowInner> win = do_QueryInterface(aTarget);
     return win ? win->GetExtantDoc() : nullptr;
   }
 
   return node->OwnerDoc();
 }
 
+void nsFocusManager::SendFocusInOrOutEvent(EventMessage aEventMessage,
+                                     nsIPresShell* aPresShell,
+                                     nsISupports* aTarget,
+                                     nsPIDOMWindowOuter* aCurrentFocusedWindow,
+                                     nsIContent* aCurrentFocusedContent,
+                                     EventTarget* aRelatedTarget)
+{
+  NS_ASSERTION(aEventMessage == eFocusIn || aEventMessage == eFocusOut,
+      "Wrong event type for SendFocusInOrOutEvent");
+
+  nsContentUtils::AddScriptRunner(
+      new FocusInOutEvent(
+        aTarget,
+        aEventMessage,
+        aPresShell->GetPresContext(),
+        aCurrentFocusedWindow,
+        aCurrentFocusedContent,
+        aRelatedTarget));
+}
+
 void
 nsFocusManager::SendFocusOrBlurEvent(EventMessage aEventMessage,
                                      nsIPresShell* aPresShell,
                                      nsIDocument* aDocument,
                                      nsISupports* aTarget,
                                      uint32_t aFocusMethod,
                                      bool aWindowRaised,
                                      bool aIsRefocus,
                                      EventTarget* aRelatedTarget)
 {
   NS_ASSERTION(aEventMessage == eFocus || aEventMessage == eBlur,
                "Wrong event type for SendFocusOrBlurEvent");
 
   nsCOMPtr<EventTarget> eventTarget = do_QueryInterface(aTarget);
   nsCOMPtr<nsIDocument> eventTargetDoc = GetDocumentHelper(eventTarget);
   nsCOMPtr<nsIDocument> relatedTargetDoc = GetDocumentHelper(aRelatedTarget);
+  nsCOMPtr<nsPIDOMWindowOuter> currentWindow = mFocusedWindow;
+  nsCOMPtr<nsPIDOMWindowInner> targetWindow = do_QueryInterface(aTarget);
+  nsCOMPtr<nsIDocument> targetDocument = do_QueryInterface(aTarget);
+  nsCOMPtr<nsIContent> currentFocusedContent = currentWindow ?
+      currentWindow->GetFocusedNode() : nullptr;
 
   // set aRelatedTarget to null if it's not in the same document as eventTarget
   if (eventTargetDoc != relatedTargetDoc) {
     aRelatedTarget = nullptr;
   }
 
   bool dontDispatchEvent =
     eventTargetDoc && nsContentUtils::IsUserFocusIgnored(eventTargetDoc);
@@ -2094,16 +2162,29 @@ nsFocusManager::SendFocusOrBlurEvent(Eve
     }
   }
 #endif
 
   if (!dontDispatchEvent) {
     nsContentUtils::AddScriptRunner(
       new FocusBlurEvent(aTarget, aEventMessage, aPresShell->GetPresContext(),
                          aWindowRaised, aIsRefocus, aRelatedTarget));
+
+    // Check that the target is not a window or document before firing
+    // focusin/focusout. Other browsers do not fire focusin/focusout on window,
+    // despite being required in the spec, so follow their behavior.
+    //
+    // As for document, we should not even fire focus/blur, but until then, we
+    // need this check. targetDocument should be removed once bug 1228802 is
+    // resolved.
+    if (!targetWindow && !targetDocument) {
+      EventMessage focusInOrOutMessage = aEventMessage == eFocus ? eFocusIn : eFocusOut;
+      SendFocusInOrOutEvent(focusInOrOutMessage, aPresShell, aTarget,
+          currentWindow, currentFocusedContent, aRelatedTarget);
+    }
   }
 }
 
 void
 nsFocusManager::ScrollIntoView(nsIPresShell* aPresShell,
                                nsIContent* aContent,
                                uint32_t aFlags)
 {

--- a/dom/base/nsFocusManager.h
+++ b/dom/base/nsFocusManager.h
@@ -292,16 +292,40 @@ protected:
                             nsIDocument* aDocument,
                             nsISupports* aTarget,
                             uint32_t aFocusMethod,
                             bool aWindowRaised,
                             bool aIsRefocus = false,
                             mozilla::dom::EventTarget* aRelatedTarget = nullptr);
 
   /**
+   *  Send a focusin or focusout event
+   *
+   *  aEventMessage should be either eFocusIn or eFocusOut.
+   *
+   *  aTarget is the content the event will fire on (the object that gained
+   *  focus for focusin, the object blurred for focusout).
+   *
+   *  aCurrentFocusedWindow is the window focused before the focus/blur event
+   *  was fired.
+   *
+   *  aCurrentFocusedContent is the content focused before the focus/blur event
+   *  was fired.
+   *
+   *  aRelatedTarget is the content related to the event (the object
+   *  losing focus for focusin, the object getting focus for focusout).
+   */
+  void SendFocusInOrOutEvent(mozilla::EventMessage aEventMessage,
+                             nsIPresShell* aPresShell,
+                             nsISupports* aTarget,
+                             nsPIDOMWindowOuter* aCurrentFocusedWindow,
+                             nsIContent* aCurrentFocusedContent,
+                             mozilla::dom::EventTarget* aRelatedTarget = nullptr);
+
+  /**
    * Scrolls aContent into view unless the FLAG_NOSCROLL flag is set.
    */
   void ScrollIntoView(nsIPresShell* aPresShell,
                       nsIContent* aContent,
                       uint32_t aFlags);
 
   /**
    * Raises the top-level window aWindow at the widget level.

--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -789,16 +789,18 @@ GK_ATOM(onenabled, "onenabled")
 GK_ATOM(onenterpincodereq, "onenterpincodereq")
 GK_ATOM(onemergencycbmodechange, "onemergencycbmodechange")
 GK_ATOM(onerror, "onerror")
 GK_ATOM(onevicted, "onevicted")
 GK_ATOM(onfailed, "onfailed")
 GK_ATOM(onfetch, "onfetch")
 GK_ATOM(onfinish, "onfinish")
 GK_ATOM(onfocus, "onfocus")
+GK_ATOM(onfocusin, "onfocusin")
+GK_ATOM(onfocusout, "onfocusout")
 GK_ATOM(onfrequencychange, "onfrequencychange")
 GK_ATOM(onfullscreenchange, "onfullscreenchange")
 GK_ATOM(onfullscreenerror, "onfullscreenerror")
 GK_ATOM(onspeakerforcedchange, "onspeakerforcedchange")
 GK_ATOM(onget, "onget")
 GK_ATOM(ongroupchange, "ongroupchange")
 GK_ATOM(onhashchange, "onhashchange")
 GK_ATOM(onheadphoneschange, "onheadphoneschange")

--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -1316,30 +1316,32 @@ nsGlobalWindow::nsGlobalWindow(nsGlobalW
   }
 
   // We could have failed the first time through trying
   // to create the entropy collector, so we should
   // try to get one until we succeed.
 
   gRefCnt++;
 
-  if (gRefCnt == 1) {
+  static bool sFirstTime = true;
+  if (sFirstTime) {
     Preferences::AddIntVarCache(&gMinTimeoutValue,
                                 "dom.min_timeout_value",
                                 DEFAULT_MIN_TIMEOUT_VALUE);
     Preferences::AddIntVarCache(&gMinBackgroundTimeoutValue,
                                 "dom.min_background_timeout_value",
                                 DEFAULT_MIN_BACKGROUND_TIMEOUT_VALUE);
     Preferences::AddBoolVarCache(&sIdleObserversAPIFuzzTimeDisabled,
                                  "dom.idle-observers-api.fuzz_time.disabled",
                                  false);
 
     Preferences::AddUintVarCache(&gThrottledIdlePeriodLength,
                                  "dom.idle_period.throttled_length",
                                  DEFAULT_THROTTLED_IDLE_PERIOD_LENGTH);
+    sFirstTime = false;
   }
 
   if (gDumpFile == nullptr) {
     const nsAdoptingCString& fname =
       Preferences::GetCString("browser.dom.window.dump.file");
     if (!fname.IsEmpty()) {
       // if this fails to open, Dump() knows to just go to stdout
       // on null.

--- a/dom/cache/test/mochitest/browser_cache_pb_window.js
+++ b/dom/cache/test/mochitest/browser_cache_pb_window.js
@@ -69,14 +69,13 @@ function test() {
     privateWin.addEventListener('load', function() {
       Promise.all([
         testMatch(privateWin),
         testHas(privateWin),
         testOpen(privateWin),
         testDelete(privateWin),
         testKeys(privateWin)
       ]).then(function() {
-        privateWin.close();
-        finish();
+        BrowserTestUtils.closeWindow(privateWin).then(finish);
       });
     });
   });
 }

--- a/dom/canvas/CanvasRenderingContext2D.cpp
+++ b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -4938,16 +4938,21 @@ CanvasRenderingContext2D::DrawImage(cons
 
   gfx::Rect bounds;
 
   if (NeedToCalculateBounds()) {
     bounds = gfx::Rect(aDx, aDy, aDw, aDh);
     bounds = mTarget->GetTransform().TransformBounds(bounds);
   }
 
+  if (!IsTargetValid()) {
+    gfxCriticalError() << "Unexpected invalid target in a Canvas2d.";
+    return;
+  }
+
   if (srcSurf) {
     gfx::Rect sourceRect(aSx, aSy, aSw, aSh);
     if (element == mCanvasElement) {
       // srcSurf is a snapshot of mTarget. If we draw to mTarget now, we'll
       // trigger a COW copy of the whole canvas into srcSurf. That's a huge
       // waste if sourceRect doesn't cover the whole canvas.
       // We avoid copying the whole canvas by manually copying just the part
       // that we need.

--- a/dom/canvas/test/test_capture.html
+++ b/dom/canvas/test/test_capture.html
@@ -93,16 +93,29 @@ function checkDrawImageNotCleanRed() {
     .then(() => h.waitForPixelColor(vmanual, h.green, 0, "should still be green"))
     .then(() => h.requestFrame(vmanual))
     .then(() => h.waitForPixelColorTimeout(vmanual, h.red, 0, 1000,
                                            "should not become red"))
     .catch(err => ok(false, "checkDrawImageNotCleanRed failed: ", err))
     .then(() => drawing.stop());
 }
 
+function checkEndedOnStop() {
+  let promises = [vauto, vmanual, vrate].map(elem => {
+    elem.srcObject.getTracks()[0].stop();
+    return new Promise(resolve =>
+      elem.addEventListener("ended", function endedListener(event) {
+        ok(true, "Element " + elem.id + " ended.");
+        resolve();
+        elem.removeEventListener("ended", endedListener);
+      }));
+  });
+  return Promise.all(promises);
+}
+
 function finish() {
   ok(true, 'Test complete.');
   SimpleTest.finish();
 }
 
 function beginTest() {
   h = new CaptureStreamTestHelper2D();
 
@@ -112,16 +125,17 @@ function beginTest() {
   vrate = h.createAndAppendElement('video', 'vrate');
 
   Promise.resolve()
     .then(checkDrawColorInitialRed)
     .then(checkDrawColorGreen)
     .then(checkRequestFrameOrderGuarantee)
     .then(checkDrawColorGreen) // Restore video elements to green.
     .then(checkDrawImageNotCleanRed)
+    .then(checkEndedOnStop)
     .then(finish);
 }
 
 SimpleTest.waitForExplicitFinish();
 
 beginTest();
 </script>
 

--- a/dom/canvas/test/webgl-mochitest/test_capture.html
+++ b/dom/canvas/test/webgl-mochitest/test_capture.html
@@ -110,16 +110,30 @@ function checkRequestFrameOrderGuarantee
   return Promise.resolve()
     .then(() => h.waitForPixelColor(vmanual, h.red, 0, "should still be red"))
     .then(() => h.drawColor(c, h.green)) // 1. Draw canvas green
     .then(() => h.requestFrame(vmanual)) // 2. Immediately request a frame
     .then(() => h.waitForPixelColor(vmanual, h.green, 0,
                                     "should become green after call order test"))
 }
 
+function checkEndedOnStop() {
+  let promises = [vauto, vmanual, vrate].map(elem => {
+    elem.srcObject.getTracks()[0].stop();
+    return new Promise(resolve =>
+      elem.addEventListener("ended", function endedListener(event) {
+        ok(true, "Element " + elem.id + " ended.");
+        resolve();
+        elem.removeEventListener("ended", endedListener);
+      }));
+  });
+  return Promise.all(promises);
+}
+
+
 function finish() {
   ok(true, 'Test complete.');
   SimpleTest.finish();
 }
 
 function beginTest() {
   h = new CaptureStreamTestHelperWebGL();
 
@@ -177,16 +191,17 @@ function beginTest() {
 
   // Run tests.
 
   Promise.resolve()
     .then(checkClearColorInitialRed)
     .then(checkDrawColorGreen)
     .then(checkClearColorRed)
     .then(checkRequestFrameOrderGuarantee)
+    .then(checkEndedOnStop)
     .then(finish);
 }
 
 SimpleTest.waitForExplicitFinish();
 
 beginTest();
 </script>
 

--- a/dom/events/ClipboardEvent.cpp
+++ b/dom/events/ClipboardEvent.cpp
@@ -48,16 +48,18 @@ ClipboardEvent::InitClipboardEvent(const
   return rv.StealNSResult();
 }
 
 void
 ClipboardEvent::InitClipboardEvent(const nsAString& aType, bool aCanBubble,
                                    bool aCancelable,
                                    DataTransfer* aClipboardData)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   Event::InitEvent(aType, aCanBubble, aCancelable);
   mEvent->AsClipboardEvent()->mClipboardData = aClipboardData;
 }
 
 already_AddRefed<ClipboardEvent>
 ClipboardEvent::Constructor(const GlobalObject& aGlobal,
                             const nsAString& aType,
                             const ClipboardEventInit& aParam,

--- a/dom/events/CommandEvent.cpp
+++ b/dom/events/CommandEvent.cpp
@@ -46,16 +46,18 @@ CommandEvent::GetCommand(nsAString& aCom
 }
 
 NS_IMETHODIMP
 CommandEvent::InitCommandEvent(const nsAString& aTypeArg,
                                bool aCanBubbleArg,
                                bool aCancelableArg,
                                const nsAString& aCommand)
 {
+  NS_ENSURE_TRUE(!mEvent->mFlags.mIsBeingDispatched, NS_OK);
+
   Event::InitEvent(aTypeArg, aCanBubbleArg, aCancelableArg);
 
   mEvent->AsCommandEvent()->mCommand = NS_Atomize(aCommand);
   return NS_OK;
 }
 
 } // namespace dom
 } // namespace mozilla

--- a/dom/events/CompositionEvent.cpp
+++ b/dom/events/CompositionEvent.cpp
@@ -59,16 +59,18 @@ CompositionEvent::GetLocale(nsAString& a
 void
 CompositionEvent::InitCompositionEvent(const nsAString& aType,
                                        bool aCanBubble,
                                        bool aCancelable,
                                        nsGlobalWindow* aView,
                                        const nsAString& aData,
                                        const nsAString& aLocale)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   UIEvent::InitUIEvent(aType, aCanBubble, aCancelable, aView, 0);
   mData = aData;
   mLocale = aLocale;
 }
 
 void
 CompositionEvent::GetRanges(TextClauseArray& aRanges)
 {

--- a/dom/events/CustomEvent.cpp
+++ b/dom/events/CustomEvent.cpp
@@ -71,16 +71,18 @@ CustomEvent::WrapObjectInternal(JSContex
 }
 
 NS_IMETHODIMP
 CustomEvent::InitCustomEvent(const nsAString& aType,
                              bool aCanBubble,
                              bool aCancelable,
                              nsIVariant* aDetail)
 {
+  NS_ENSURE_TRUE(!mEvent->mFlags.mIsBeingDispatched, NS_OK);
+
   AutoJSAPI jsapi;
   NS_ENSURE_STATE(jsapi.Init(GetParentObject()));
   JSContext* cx = jsapi.cx();
   JS::Rooted<JS::Value> detail(cx);
 
   if (!aDetail) {
     detail = JS::NullValue();
   } else if (NS_WARN_IF(!VariantToJsval(cx, aDetail, &detail))) {
@@ -97,16 +99,18 @@ CustomEvent::InitCustomEvent(const nsASt
 void
 CustomEvent::InitCustomEvent(JSContext* aCx,
                              const nsAString& aType,
                              bool aCanBubble,
                              bool aCancelable,
                              JS::Handle<JS::Value> aDetail,
                              ErrorResult& aRv)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   Event::InitEvent(aType, aCanBubble, aCancelable);
   mDetail = aDetail;
 }
 
 NS_IMETHODIMP
 CustomEvent::GetDetail(nsIVariant** aDetail)
 {
   if (mDetail.isNull()) {

--- a/dom/events/DeviceMotionEvent.cpp
+++ b/dom/events/DeviceMotionEvent.cpp
@@ -46,16 +46,18 @@ DeviceMotionEvent::InitDeviceMotionEvent
                      bool aCanBubble,
                      bool aCancelable,
                      const DeviceAccelerationInit& aAcceleration,
                      const DeviceAccelerationInit& aAccelIncludingGravity,
                      const DeviceRotationRateInit& aRotationRate,
                      Nullable<double> aInterval,
                      Nullable<uint64_t> aTimeStamp)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   Event::InitEvent(aType, aCanBubble, aCancelable);
 
   mAcceleration = new DeviceAcceleration(this, aAcceleration.mX,
                                          aAcceleration.mY,
                                          aAcceleration.mZ);
 
   mAccelerationIncludingGravity =
     new DeviceAcceleration(this, aAccelIncludingGravity.mX,

--- a/dom/events/DragEvent.cpp
+++ b/dom/events/DragEvent.cpp
@@ -50,16 +50,18 @@ DragEvent::InitDragEvent(const nsAString
                          bool aCtrlKey,
                          bool aAltKey,
                          bool aShiftKey,
                          bool aMetaKey,
                          uint16_t aButton,
                          EventTarget* aRelatedTarget,
                          DataTransfer* aDataTransfer)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   MouseEvent::InitMouseEvent(aType, aCanBubble, aCancelable,
                              aView, aDetail, aScreenX, aScreenY,
                              aClientX, aClientY, aCtrlKey, aAltKey,
                              aShiftKey, aMetaKey, aButton, aRelatedTarget);
   if (mEventIsInternal) {
     mEvent->AsDragEvent()->mDataTransfer = aDataTransfer;
   }
 }

--- a/dom/events/EventNameList.h
+++ b/dom/events/EventNameList.h
@@ -498,16 +498,24 @@ FORWARDED_EVENT(blur,
 ERROR_EVENT(error,
             eLoadError,
             EventNameType_All,
             eBasicEventClass)
 FORWARDED_EVENT(focus,
                 eFocus,
                 EventNameType_HTMLXUL,
                 eFocusEventClass)
+FORWARDED_EVENT(focusin,
+                eFocusIn,
+                EventNameType_HTMLXUL,
+                eFocusEventClass)
+FORWARDED_EVENT(focusout,
+                eFocusOut,
+                EventNameType_HTMLXUL,
+                eFocusEventClass)
 FORWARDED_EVENT(load,
                 eLoad,
                 EventNameType_All,
                 eBasicEventClass)
 FORWARDED_EVENT(resize,
                 eResize,
                 EventNameType_All,
                 eBasicEventClass)

--- a/dom/events/FocusEvent.cpp
+++ b/dom/events/FocusEvent.cpp
@@ -44,16 +44,18 @@ FocusEvent::GetRelatedTarget()
 void
 FocusEvent::InitFocusEvent(const nsAString& aType,
                            bool aCanBubble,
                            bool aCancelable,
                            nsGlobalWindow* aView,
                            int32_t aDetail,
                            EventTarget* aRelatedTarget)
 {
+  MOZ_ASSERT(!mEvent->mFlags.mIsBeingDispatched);
+
   UIEvent::InitUIEvent(aType, aCanBubble, aCancelable, aView, aDetail);
   mEvent->AsFocusEvent()->mRelatedTarget = aRelatedTarget;
 }
 
 already_AddRefed<FocusEvent>
 FocusEvent::Constructor(const GlobalObject& aGlobal,
                         const nsAString& aType,
                         const FocusEventInit& aParam,

--- a/dom/events/KeyboardEvent.cpp
+++ b/dom/events/KeyboardEvent.cpp
@@ -332,16 +332,18 @@ KeyboardEvent::InitKeyEvent(const nsAStr
                             mozIDOMWindow* aView,
                             bool aCtrlKey,
                             bool aAltKey,
                             bool aShiftKey,
                             bool aMetaKey,
                             uint32_t aKeyCode,
                             uint32_t aCharCode)
 {
+  NS_ENSURE_TRUE(!mEvent->mFlags.mIsBeingDispatched, NS_OK);
+
   UIEvent::InitUIEvent(aType, aCanBubble, aCancelable, aView, 0);
 
   WidgetKeyboardEvent* keyEvent = mEvent->AsKeyboardEvent();
   keyEvent->InitBasicModifiers(aCtrlKey, aAltKey, aShiftKey, aMetaKey);
   keyEvent->mKeyCode = aKeyCode;
   keyEvent->mCharCode = aCharCode;
 
   return NS_OK;

--- a/dom/events/MessageEvent.cpp
+++ b/dom/events/MessageEvent.cpp
@@ -141,16 +141,18 @@ void
 MessageEvent::InitMessageEvent(JSContext* aCx, const nsAString& aType,
                                bool aCanBubble, bool aCancelable,
                                JS::Handle<JS::Value> aData,
                                const nsAString& aOrigin,
                                const nsAString& aLastEventId,
                                const Nullable<WindowProxyOrMessagePort>& aSource,
                                const Sequence<OwningNonNull<MessagePort>>& aPorts)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   Event::InitEvent(aType, aCanBubble, aCancelable);
   mData = aData;
   mozilla::HoldJSObjects(this);
   mOrigin = aOrigin;
   mLastEventId = aLastEventId;
 
   mWindowSource = nullptr;
   mPortSource = nullptr;

--- a/dom/events/MouseEvent.cpp
+++ b/dom/events/MouseEvent.cpp
@@ -62,16 +62,18 @@ MouseEvent::InitMouseEvent(const nsAStri
                            int32_t aClientY,
                            bool aCtrlKey,
                            bool aAltKey,
                            bool aShiftKey,
                            bool aMetaKey,
                            uint16_t aButton,
                            EventTarget* aRelatedTarget)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   UIEvent::InitUIEvent(aType, aCanBubble, aCancelable, aView, aDetail);
 
   switch(mEvent->mClass) {
     case eMouseEventClass:
     case eMouseScrollEventClass:
     case eWheelEventClass:
     case eDragEventClass:
     case ePointerEventClass:
@@ -133,16 +135,18 @@ MouseEvent::InitMouseEvent(const nsAStri
                            int32_t aScreenX,
                            int32_t aScreenY,
                            int32_t aClientX,
                            int32_t aClientY,
                            int16_t aButton,
                            EventTarget* aRelatedTarget,
                            const nsAString& aModifiersList)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   Modifiers modifiers = ComputeModifierState(aModifiersList);
 
   InitMouseEvent(aType, aCanBubble, aCancelable, aView, aDetail,
                  aScreenX, aScreenY, aClientX, aClientY,
                  (modifiers & MODIFIER_CONTROL) != 0,
                  (modifiers & MODIFIER_ALT) != 0,
                  (modifiers & MODIFIER_SHIFT) != 0,
                  (modifiers & MODIFIER_META) != 0,
@@ -205,16 +209,18 @@ MouseEvent::InitNSMouseEvent(const nsASt
                              bool aAltKey,
                              bool aShiftKey,
                              bool aMetaKey,
                              uint16_t aButton,
                              EventTarget* aRelatedTarget,
                              float aPressure,
                              uint16_t aInputSource)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   MouseEvent::InitMouseEvent(aType, aCanBubble, aCancelable,
                              aView, aDetail, aScreenX, aScreenY,
                              aClientX, aClientY,
                              aCtrlKey, aAltKey, aShiftKey,
                              aMetaKey, aButton, aRelatedTarget);
 
   WidgetMouseEventBase* mouseEventBase = mEvent->AsMouseEventBase();
   mouseEventBase->pressure = aPressure;

--- a/dom/events/MouseScrollEvent.cpp
+++ b/dom/events/MouseScrollEvent.cpp
@@ -51,16 +51,18 @@ MouseScrollEvent::InitMouseScrollEvent(c
                                        bool aCtrlKey,
                                        bool aAltKey,
                                        bool aShiftKey,
                                        bool aMetaKey,
                                        uint16_t aButton,
                                        EventTarget* aRelatedTarget,
                                        int32_t aAxis)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   MouseEvent::InitMouseEvent(aType, aCanBubble, aCancelable, aView, aDetail,
                              aScreenX, aScreenY, aClientX, aClientY,
                              aCtrlKey, aAltKey, aShiftKey, aMetaKey, aButton,
                              aRelatedTarget);
   mEvent->AsMouseScrollEvent()->mIsHorizontal =
     (aAxis == nsIDOMMouseScrollEvent::HORIZONTAL_AXIS);
 }
 

--- a/dom/events/MutationEvent.cpp
+++ b/dom/events/MutationEvent.cpp
@@ -91,16 +91,18 @@ MutationEvent::InitMutationEvent(const n
                                  bool aCanBubbleArg,
                                  bool aCancelableArg,
                                  nsIDOMNode* aRelatedNodeArg,
                                  const nsAString& aPrevValueArg,
                                  const nsAString& aNewValueArg,
                                  const nsAString& aAttrNameArg,
                                  uint16_t aAttrChangeArg)
 {
+  NS_ENSURE_TRUE(!mEvent->mFlags.mIsBeingDispatched, NS_OK);
+
   Event::InitEvent(aTypeArg, aCanBubbleArg, aCancelableArg);
 
   InternalMutationEvent* mutation = mEvent->AsMutationEvent();
   mutation->mRelatedNode = aRelatedNodeArg;
   if (!aPrevValueArg.IsEmpty())
     mutation->mPrevAttrValue = NS_Atomize(aPrevValueArg);
   if (!aNewValueArg.IsEmpty())
     mutation->mNewAttrValue = NS_Atomize(aNewValueArg);

--- a/dom/events/ScrollAreaEvent.cpp
+++ b/dom/events/ScrollAreaEvent.cpp
@@ -34,16 +34,18 @@ ScrollAreaEvent::InitScrollAreaEvent(con
                                      bool aCancelable,
                                      nsGlobalWindow* aView,
                                      int32_t aDetail,
                                      float aX,
                                      float aY,
                                      float aWidth,
                                      float aHeight)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   UIEvent::InitUIEvent(aEventType, aCanBubble, aCancelable, aView, aDetail);
   mClientArea->SetRect(aX, aY, aWidth, aHeight);
 }
 
 NS_IMETHODIMP_(void)
 ScrollAreaEvent::Serialize(IPC::Message* aMsg,
                            bool aSerializeInterfaceType)
 {

--- a/dom/events/SimpleGestureEvent.cpp
+++ b/dom/events/SimpleGestureEvent.cpp
@@ -119,16 +119,18 @@ SimpleGestureEvent::InitSimpleGestureEve
                                            bool aMetaKeyArg,
                                            uint16_t aButton,
                                            EventTarget* aRelatedTarget,
                                            uint32_t aAllowedDirectionsArg,
                                            uint32_t aDirectionArg,
                                            double aDeltaArg,
                                            uint32_t aClickCountArg)
 {
+  NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
+
   MouseEvent::InitMouseEvent(aTypeArg, aCanBubbleArg, aCancelableArg,
                              aViewArg, aDetailArg,
                              aScreenX, aScreenY, aClientX, aClientY,
                              aCtrlKeyArg, aAltKeyArg, aShiftKeyArg,
                              aMetaKeyArg, aButton, aRelatedTarget);
 
   WidgetSimpleGestureEvent* simpleGestureEvent = mEvent->AsSimpleGestureEvent();
   simpleGestureEvent->mAllowedDirections = aAllowedDirectionsArg;