Fix warnings and errors in ChromeVox since Closure compiler update.

chrome/browser/resources/chromeos/chromevox/cvox2/background/output.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 Provides output services for ChromeVox.
  */
 
 goog.provide('Output');
 goog.provide('Output.EventType');
@@ skipping 518 matching lines @@
                   node.attributes.textSelEnd));
             }
           }
           // Annotate this as a name so we don't duplicate names from ancestors.
           if (node.role == chrome.automation.RoleType.inlineTextBox)
             token = 'name';
           options.annotation.push(token);
           this.append_(buff, text, options);
         } else if (token == 'indexInParent') {
           options.annotation.push(token);
-          this.append_(buff, node.indexInParent + 1);
+          this.append_(buff, String(node.indexInParent + 1));
         } else if (token == 'parentChildCount') {
           options.annotation.push(token);
           if (node.parent)
-          this.append_(buff, node.parent.children.length);
+          this.append_(buff, String(node.parent.children.length));
         } else if (token == 'state') {
           options.annotation.push(token);
           Object.getOwnPropertyNames(node.state).forEach(function(s) {
             this.append_(buff, s, options);
           }.bind(this));
         } else if (token == 'find') {
           // Find takes two arguments: JSON query string and format string.
           if (tree.firstChild) {
             var jsonQuery = tree.firstChild.value;
             node = node.find(
@@ skipping 313 matching lines @@
     }
 
     if (currentNode != root)
       throw 'Unbalanced parenthesis.';
 
     return root;
   }
 };
 
 });  // goog.scope