Wire up an api to darken screen for accessibility

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 321 matching lines @@
                        category: 'information'},
   'toggleSelection': {announce: true,
                       msgId: 'toggle_selection',
                       category: 'information'},
 
   'toggleSearchWidget': {announce: false,
                          disallowContinuation: true,
                          msgId: 'toggle_search_widget',
                          category: 'information'},
 
+  'undarkenScreen': {
+    msgId: 'undarken_screen',
+    category: 'help_commands'
+  },
+
+  'darkenScreen': {
+    msgId: 'darken_screen',
+    category: 'help_commands'
+},
+
   'toggleKeyboardHelp': {announce: false,
                          disallowContinuation: true,
                          msgId: 'show_power_key',
                          category: 'help_commands'},
   'help': {announce: false,
            msgId: 'help',
            'disallowOOBE': true,
            disallowContinuation: true,
            category: 'help_commands'},
   'contextMenu': {announce: false,
@@ skipping 436 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'}
 };