Handle authentication failures in the v2 app by restarting the app

remoting/webapp/base/js/base.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * A module that contains basic utility components and methods for the
  * chromoting project
  *
  */
@@ skipping 449 matching lines @@
  * @param {string} jsonString A JSON-encoded string.
  * @return {Object|undefined} The decoded object, or undefined if the string
  *     cannot be parsed.
  */
 base.jsonParseSafe = function(jsonString) {
   try {
     return /** @type {Object} */ (JSON.parse(jsonString));
   } catch (err) {
     return undefined;
   }
-}
+};
+
+/**
+ * @return {boolean} whether the calling script is executing in the background
+ *   page or not.
+ */
+base.isBackgroundPage = function() {
+  return base.isAppsV2() && !Boolean(chrome.app.window.current());
+};