Implement update notifications for ChromeVox Next.

chrome/browser/resources/chromeos/chromevox/chromevox/injected/user_commands.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 High level commands that the user can invoke using hotkeys.
  *
  * Usage:
  * If you are here, you probably want to add a new user command. Here are some
  * general steps to get you started.
@@ skipping 540 matching lines @@
       break;
     case 'toggleChromeVox':
       cvox.ChromeVox.host.sendToBackgroundPage({
         'target': 'Prefs',
         'action': 'setPref',
         'pref': 'active',
         'value': !cvox.ChromeVox.isActive
       });
       break;
     case 'toggleChromeVoxVersion':
+    case 'showNextUpdatePage':
       cvox.ChromeVox.host.sendToBackgroundPage({
-        'target': 'toggleChromeVoxVersion'
+        'target': 'next',
+        'action': cmd
       });
       break;
     case 'fullyDescribe':
       var descs = cvox.ChromeVox.navigationManager.getFullDescription();
       cvox.ChromeVox.navigationManager.speakDescriptionArray(
           descs,
           cvox.QueueMode.FLUSH,
           null);
       break;
     case 'speakTimeAndDate':
@@ skipping 246 matching lines @@
   cmdStruct = goog.object.clone(cmdStruct);
   cmdStruct.command = cmd;
   if (opt_kwargs) {
     goog.object.extend(cmdStruct, opt_kwargs);
   }
   return cmdStruct;
 };
 
 
 cvox.ChromeVoxUserCommands.init_();