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

chrome/browser/resources/chromeos/chromevox/walkers/structural_line_walker.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 A JavaScript class for walking lines.
  */
 
 
 goog.provide('cvox.StructuralLineWalker');
@@ skipping 10 matching lines @@
   goog.base(this);
   this.grain = cvox.TraverseContent.kLine;
 };
 goog.inherits(cvox.StructuralLineWalker, cvox.AbstractSelectionWalker);
 
 
 /**
  * @override
  */
 cvox.StructuralLineWalker.prototype.getGranularityMsg = function() {
-  return cvox.ChromeVox.msgs.getMsg('structural_line');
+  return Msgs.getMsg('structural_line');
 };
 
 
 /**
  * @override
  */
 cvox.StructuralLineWalker.prototype.getDescription = function(prevSel, sel) {
   var desc = goog.base(this, 'getDescription', prevSel, sel);
   desc[0].text = cvox.DomUtil.getPrefixText(
       sel.absStart().node, sel.absStart().index) + desc[0].text;
@@ skipping 27 matching lines @@
   var spannable =
       cvox.BrailleUtil.getTemplated(prevNode, objNode, {name: name});
   spannable.setSpan(objNode, 0, spannable.getLength());
   braille.text = spannable;
 
   // Remove any selections.
   braille.startIndex = 0;
   braille.endIndex = 0;
   return braille;
 };