On active, dismiss the retail mode screensaver immidiately.

chrome/browser/chromeos/kiosk_mode/kiosk_mode_screensaver.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_CHROMEOS_KIOSK_MODE_KIOSK_MODE_SCREENSAVER_H_
 #define CHROME_BROWSER_CHROMEOS_KIOSK_MODE_KIOSK_MODE_SCREENSAVER_H_
 
 #include "ash/wm/user_activity_observer.h"
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/memory/weak_ptr.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
 
 namespace extensions {
 class Extension;
 }
 
 namespace chromeos {
 
-class KioskModeScreensaver : public ash::UserActivityObserver,
-                             public content::NotificationObserver {
+class KioskModeScreensaver : public ash::UserActivityObserver {
  public:
   KioskModeScreensaver();
   virtual ~KioskModeScreensaver();
 
  private:
   friend class KioskModeScreensaverTest;
 
-  // NotificationObserver overrides:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
   // UserActivityObserver::Observer overrides:
   virtual void OnUserActivity() OVERRIDE;
 
   // Initialization functions, in order
   // Get the screensaver path once KioskModeHelper is initialized.
   void GetScreensaverCrxPath();
 
   // Callback to receive the path to the screensaver extension's crx and call
   // the unpacker to unpack and load the crx.
   void ScreensaverPathCallback(const FilePath& screensaver_crx);
 
   // Called back on the UI thread to Setup the screensaver with the now unpacked
   // and loaded extension.
   void SetupScreensaver(scoped_refptr<extensions::Extension> extension,
                         const FilePath& extension_base_path);
 
-  content::NotificationRegistrar registrar_;
   base::WeakPtrFactory<KioskModeScreensaver> weak_ptr_factory_;
 
   FilePath extension_base_path_;
 
   DISALLOW_COPY_AND_ASSIGN(KioskModeScreensaver);
 };
 
 void InitializeKioskModeScreensaver();
 void ShutdownKioskModeScreensaver();
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_KIOSK_MODE_KIOSK_MODE_SCREENSAVER_H_