Bug 1381853 - lazy load browser-customization.js into the browser window, r=mconley.

browser/base/content/browser-customization.js

@@ -3,6 +3,9 @@
  * 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/. */
 
+// This file is loaded into the browser window scope.
+/* eslint-env mozilla/browser-window */
+
 /**
  * Customization handler prepares this browser window for entering and exiting
  * customization mode by handling customizationstarting and customizationending

browser/base/content/browser-tabsintitlebar.js

@@ -259,7 +259,7 @@ var TabsInTitlebar = {
 
     ToolbarIconColor.inferFromText("tabsintitlebar", TabsInTitlebar.enabled);
 
-    if (CustomizationHandler.isCustomizing()) {
+    if (document.documentElement.hasAttribute("customizing")) {
       gCustomizeMode.updateLWTStyling();
     }
   },

browser/base/content/browser.js

@@ -118,6 +118,8 @@ XPCOMUtils.defineLazyScriptGetter(this, ["LightWeightThemeWebInstaller",
                                   "chrome://browser/content/browser-addons.js");
 XPCOMUtils.defineLazyScriptGetter(this, "ctrlTab",
                                   "chrome://browser/content/browser-ctrlTab.js");
+XPCOMUtils.defineLazyScriptGetter(this, "CustomizationHandler",
+                                  "chrome://browser/content/browser-customization.js");
 
 
 // lazy service getters

browser/base/content/global-scripts.inc

@@ -10,7 +10,6 @@
 <script type="application/javascript" src="chrome://browser/content/browser.js"/>
 
 <script type="application/javascript" src="chrome://browser/content/browser-captivePortal.js"/>
-<script type="application/javascript" src="chrome://browser/content/browser-customization.js"/>
 <script type="application/javascript" src="chrome://browser/content/browser-compacttheme.js"/>
 <script type="application/javascript" src="chrome://browser/content/browser-feeds.js"/>
 <script type="application/javascript" src="chrome://browser/content/browser-fullScreenAndPointerLock.js"/>