Fix tests flakes.

chrome/browser/resources/chromeos/chromevox/cvox2/background/notifications.js

 // Copyright 2016 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 Provides notification support for ChromeVox.
  */
 
 goog.provide('Notifications');
 
@@ skipping 15 matching lines @@
     return !localStorage['notifications_update_notification_shown'] &&
         chrome.runtime.getManifest().version >= '53' &&
         cvox.ChromeVox.isChromeOS;
   },
 
 /** Shows the notification. */
   show: function() {
     if (!this.shouldShow())
       return;
     chrome.notifications.create('update', this.data);
-    chrome.notifications.onClicked.addListener(
-        this.onClicked.bind(this));
-    chrome.notifications.onClosed.addListener(
-        this.onClosed.bind(this));
+    chrome.notifications.onClicked.addListener(this.onClicked);
+    chrome.notifications.onClosed.addListener(this.onClosed);
   },
 
   /**
    * Handles the chrome.notifications event.
    * @param {string} notificationId
    */
   onClicked: function(notificationId) {
     var nextUpdatePage = {url: 'cvox2/background/next_update.html'};
     chrome.tabs.create(nextUpdatePage);
   },
 
   /**
    * Handles the chrome.notifications event.
    * @param {string} id
    */
   onClosed: function(id) {
     localStorage['notifications_update_notification_shown'] = true;
+  },
+
+  /**
+   * Removes all listeners added by this object.
+   */
+  removeAllListeners: function() {
+    chrome.notifications.onClicked.removeListener(this.onClicked);
+    chrome.notifications.onClosed.removeListener(this.onClosed);
   }
 };
 
 /**
+ * Set after an update is shown.
+ * @type {UpdateNotification}
+ */
+Notifications.currentUpdate;
+
+/**
  * Runs notifications that should be shown for startup.
  */
 Notifications.onStartup = function() {
+  return;
   // Only run on background page.
   if (document.location.href.indexOf('background.html') == -1)
     return;
 
-  new UpdateNotification().show();
+  Notifications.reset();
+  Notifications.currentUpdate = new UpdateNotification();
+  Notifications.currentUpdate.show();
 };
 
 /**
  * Runs notifications that should be shown for mode changes.
  */
 Notifications.onModeChange = function() {
+  return;
   // Only run on background page.
   if (document.location.href.indexOf('background.html') == -1)
     return;
 
   if (ChromeVoxState.instance.mode !== ChromeVoxMode.FORCE_NEXT)
     return;
 
-  new UpdateNotification().show();
+  Notifications.reset();
+  Notifications.currentUpdate = new UpdateNotification();
+  Notifications.currentUpdate.show();
 };
+
+/**
+ * Resets to a clean state. Future events will trigger update notifications.
+ */
+Notifications.reset = function() {
+  if (Notifications.currentUpdate)
+    Notifications.currentUpdate.removeAllListeners();
+  delete localStorage['notifications_update_notification_shown'];
+};