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

chrome/browser/ui/webui/help/help_handler.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_HELP_HELP_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_HELP_HELP_HANDLER_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "chrome/browser/ui/webui/help/version_updater.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_ui_message_handler.h"
 
 #if defined(OS_CHROMEOS)
+#include "base/memory/weak_ptr.h"
+#include "base/platform_file.h"
 #include "chrome/browser/chromeos/version_loader.h"
 #endif  // defined(OS_CHROMEOS)
 
 // WebUI message handler for the help page.
 class HelpHandler : public content::WebUIMessageHandler,
                     public content::NotificationObserver {
  public:
   HelpHandler();
   virtual ~HelpHandler();
 
@@ skipping 38 matching lines @@
   // Callback method which forwards promotion state to the page.
   void SetPromotionState(VersionUpdater::PromotionState state);
 #endif
 
 #if defined(OS_CHROMEOS)
   // Callbacks from VersionLoader.
   void OnOSVersion(chromeos::VersionLoader::Handle handle, std::string version);
   void OnOSFirmware(chromeos::VersionLoader::Handle handle,
                     std::string firmware);
   void OnReleaseChannel(const std::string& channel);
+
+  void ProcessLsbFileInfo(
+      base::PlatformFileError rv, const base::PlatformFileInfo& file_info);
 #endif
 
   // Specialized instance of the VersionUpdater used to update the browser.
   scoped_ptr<VersionUpdater> version_updater_;
 
   // Used to observe notifications.
   content::NotificationRegistrar registrar_;
 
 #if defined(OS_CHROMEOS)
+  // Used for callbacks.
+  base::WeakPtrFactory<HelpHandler> weak_factory_;
+
   // Handles asynchronously loading the CrOS version info.
   chromeos::VersionLoader loader_;
 
   // Used to request the version.
   CancelableRequestConsumer consumer_;
 #endif  // defined(OS_CHROMEOS)
 
   DISALLOW_COPY_AND_ASSIGN(HelpHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_HELP_HELP_HANDLER_H_