Improve braille related message descriptions and clean up message handling in Chromevox.

chrome/browser/resources/chromeos/chromevox/common/chromevox.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 Defines a global object. The initialization of this
  *   object happens in init.js.
  *
  */
 
@@ skipping 19 matching lines @@
     ['cvox.BrailleInterface'],
     []);
 
 goog.addDependency(
     '../host/interface/mathjax_interface.js',
     ['cvox.MathJaxInterface'],
     []);
 
 goog.addDependency(
     '../chromevox/messages/msgs.js',
-    ['cvox.Msgs'],
+    ['Msgs'],
     []);
 
 goog.addDependency(
     '../host/interface/abstract_earcons.js',
     ['cvox.AbstractEarcons'],
     []);
 
 goog.addDependency(
     '../chromevox/common/key_sequence.js',
     ['cvox.KeySequence'],
@@ skipping 39 matching lines @@
 cvox.ChromeVox.tts;
 /**
  * @type {cvox.BrailleInterface}
  */
 cvox.ChromeVox.braille;
 /**
  * @type {cvox.MathJaxInterface}
  */
 cvox.ChromeVox.mathJax;
 /**
- * @type {cvox.Msgs}
- */
-cvox.ChromeVox.msgs = null;
-/**
  * @type {boolean}
  */
 cvox.ChromeVox.isActive = true;
 /**
  * @type {?string}
  */
 cvox.ChromeVox.version = null;
 /**
  * @type {cvox.AbstractEarcons}
  */
@@ skipping 171 matching lines @@
 cvox.ChromeVox.documentHasFocus = function() {
   if (!document.hasFocus() || document.hidden) {
     return false;
   }
   if (document.activeElement.tagName == 'IFRAME' ||
       document.activeElement.tagName == 'WEBVIEW') {
     return false;
   }
   return true;
 };