[Chromoting] Fix broken OK/Cancel button in loading window.

remoting/webapp/base/js/message_window.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.
 
 'use strict';
 
 /**
  * @constructor
  */
 function MessageWindowImpl() {
   /**
    * Used to prevent multiple responses due to the closeWindow handler.
    *
    * @type {boolean}
    * @private
    */
   this.sentReply_ = false;
 
   window.addEventListener('message', this.onMessage_.bind(this), false);
 };
 
 /**
  * @param {Window} parentWindow The id of the window that showed the message.
- * @param {string} messageId The identifier of the message, as supplied by the
+ * @param {number} messageId The identifier of the message, as supplied by the
  *     parent.
  * @param {number} result 0 if window was closed without pressing a button;
  *     otherwise the index of the button pressed (e.g., 1 = primary).
  * @private
  */
 MessageWindowImpl.prototype.sendReply_ = function(
     parentWindow, messageId, result) {
   // Only forward the first reply that we receive.
   if (!this.sentReply_) {
     var message = {
@@ skipping 83 matching lines @@
       if (showSpinner) {
         messageDiv.classList.add('waiting');
         messageDiv.classList.add('prominent');
       }
       if (infobox != '') {
         infoboxDiv.innerText = infobox;
       } else {
         infoboxDiv.hidden = true;
       }
 
-      var messageIdStr = messageId.toString();
-
       this.initButton_(
           button,
           buttonLabel,
-          this.sendReply_.bind(this, event.source, messageIdStr, 1));
+          this.sendReply_.bind(this, event.source, messageId, 1));
 
       this.initButton_(
           cancelButton,
           cancelButtonLabel,
-          this.sendReply_.bind(this, event.source, messageIdStr, 0));
+          this.sendReply_.bind(this, event.source, messageId, 0));
 
       var buttonToFocus = (cancelButtonLabel) ? cancelButton : button;
       buttonToFocus.focus();
 
       // Add a close handler in case the window is closed without clicking one
       // of the buttons. This will send a 0 as the result.
       // Note that when a button is pressed, this will result in sendReply_
       // being called multiple times (once for the button, once for close).
       chrome.app.window.current().onClosed.addListener(
-          this.sendReply_.bind(this, event.source, messageIdStr, 0));
+          this.sendReply_.bind(this, event.source, messageId, 0));
 
       this.updateSize_();
       chrome.app.window.current().show();
       break;
 
     case 'update_message':
       var message = /** @type {string} */ (event.data['message']);
       if (typeof(message) != 'string') {
         console.log('Bad update_message message:', event.data);
         break;
       }
 
       var messageDiv = document.getElementById('message');
       messageDiv.innerText = message;
 
       this.updateSize_();
       break;
 
     default:
       console.error('Unexpected message:', event.data);
   }
 };
 
 var messageWindow = new MessageWindowImpl();