Implemented a "Last Updated" field for the about page of Chrome OS.

chrome/browser/resources/help/help.js

 // Copyright (c) 2012 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 src="../uber/uber_utils.js">
 
 cr.define('help', function() {
   var localStrings = new LocalStrings();
 
   /**
@@ skipping 195 matching lines @@
           option.selected = true;
       }
     },
 
     /**
      * @private
      */
     setReleaseChannel_: function(channel) {
       chrome.send('setReleaseTrack', [channel]);
     },
+
+    /**
+     * Sets the value of the "Last Updated" field of the "More Info" section.
+     * @param {String} lastUpdated The date of the last update.
+     * @private
+     */
+    setLastUpdated_: function(lastUpdated) {
+      $('last-updated-container').classList.remove('empty');
+      $('last-updated').textContent = lastUpdated;
+    },
   };
 
   HelpPage.setUpdateStatus = function(status, message) {
     HelpPage.getInstance().setUpdateStatus_(status, message);
   };
 
   HelpPage.setProgress = function(progress) {
     HelpPage.getInstance().setProgress_(progress);
   };
 
@@ skipping 18 matching lines @@
   };
 
   HelpPage.updateEnableReleaseChannel = function(enabled) {
     HelpPage.getInstance().updateEnableReleaseChannel_(enabled);
   };
 
   HelpPage.setReleaseChannel = function(channel) {
     HelpPage.getInstance().setReleaseChannel_(channel);
   };
 
+  HelpPage.setLastUpdated = function(lastUpdated) {
+    HelpPage.getInstance().setLastUpdated_(lastUpdated);
+  }
+
   // Export
   return {
     HelpPage: HelpPage
   };
 });
 
 /**
  * onload listener to initialize the HelpPage.
  */
 window.onload = function() {
   help.HelpPage.getInstance().initialize();
 };