Implement update notifications for ChromeVox Next.

chrome/browser/resources/chromeos/chromevox/common/command_store.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 This class acts as the persistent store for all static data
  * about commands.
  *
  * This store can safely be used within either a content or background script
@@ skipping 137 matching lines @@
   'stopSpeech': {announce: false,
                  disallowContinuation: true,
                  doDefault: true,
                  msgId: 'stop_speech_key',
                  category: 'controlling_speech'},
   'toggleChromeVox': {announce: false,
                       platformFilter: cvox.PlatformFilter.WML,
                       msgId: 'toggle_chromevox_active',
                       category: 'modifier_keys'},
   'toggleChromeVoxVersion': {announce: false},
+  'showNextUpdatePage': {announce: false},

[dmazzoni, 2016/06/09 15:45:02]

Add a category for this so it shows up in the ChromeVox menus

[David Tseng, 2016/06/09 18:47:00]

Done.

   'openChromeVoxMenus': {announce: false,
                          msgId: 'menus_title'},
   'decreaseTtsRate': {announce: false,
                       msgId: 'decrease_tts_rate',
                       category: 'controlling_speech'},
   'increaseTtsRate': {announce: false,
                       msgId: 'increase_tts_rate',
                       category: 'controlling_speech'},
   'decreaseTtsPitch': {announce: false,
                       msgId: 'decrease_tts_pitch',
@@ skipping 611 matching lines @@
   'media': {predicate: 'mediaPredicate',
             forwardError: 'no_next_media_widget',
             backwardError: 'no_previous_media_widget'},
   'section': {predicate: 'sectionPredicate',
            forwardError: 'no_next_section',
            backwardError: 'no_previous_section'},
   'control': {predicate: 'controlPredicate',
            forwardError: 'no_next_control',
            backwardError: 'no_previous_control'}
 };