Prepare ChromeVox for webstore release.

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');
 
 /**
  * ChromeVox update notification.
  * @constructor
  */
 function UpdateNotification() {
   this.data = {};
   this.data.type = 'basic';
   this.data.iconUrl = '/images/chromevox-16.png';
   this.data.title = Msgs.getMsg('update_title');
   this.data.message = Msgs.getMsg('update_message_next');
 }
 
 UpdateNotification.prototype = {
   /** @return {boolean} */
   shouldShow: function() {
     return !localStorage['notifications_update_notification_shown'] &&
-        chrome.runtime.getManifest().version >= '53';
+        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(
@@ skipping 35 matching lines @@
 Notifications.onModeChange = function() {
   // 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();
 };