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

chrome/browser/resources/chromeos/chromevox/common/editable_text_test.unitjs

 // 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.
 
 // Include test fixture.
 GEN_INCLUDE(['../testing/chromevox_unittest_base.js']);
 
 /**
  * A TTS class implementing speak and stop methods intended only for testing.
  * @constructor
@@ skipping 96 matching lines @@
   /** @override */
   setUp: function() {
     // TODO: These tests are all assuming we used the IBeam cursor.
     // We need to add coverage for block cursor.
     cvox.ChromeVoxEditableTextBase.useIBeamCursor = true;
     cvox.ChromeVox.typingEcho = cvox.TypingEcho.CHARACTER_AND_WORD;
     cvox.ChromeVoxEditableTextBase.eventTypingEcho = false;
     cvox.ChromeVox.braille = new TestBraille();
 
     /** Simple mock. */
-    cvox.ChromeVox.msgs = {};
+    Msgs = {};
 
     /**
      * Simply return the message id.
      * @param {string} msg Message id.
      * @return {string} Message id.
      */
-    cvox.ChromeVox.msgs.getMsg = function(msg) {
+    Msgs.getMsg = function(msg) {
       return msg;
     };
   },
 
   /**
    * Sets up for a cursor movement test.
    * @param {string} tagName Desired tag name, "input" or "textarea".
    * @return {Object} object containing the editable element, and functions
    *     to prepare, run the test, and tear down.
    * @private
@@ skipping 549 matching lines @@
   var firstLine = 'Some   text.\n';
   for (var i = 0; i < firstLine.length; ++i) {
     editable.update(true);
     TestBraille.assertContent(firstLine, i, i);
     window.getSelection().modify('move', 'forward', 'character');
   }
   // We should have crossed the line break to the second line which is blank.
   editable.update(true);
   TestBraille.assertContent('', 0, 0);
 });