Split PrefService into PrefService, PrefServiceSimple and PrefServiceSyncable.

chrome/browser/notifications/notification_prefs_manager.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_NOTIFICATIONS_NOTIFICATION_PREFS_MANAGER_H_
 #define CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_PREFS_MANAGER_H_
 
 #include "chrome/browser/notifications/balloon_collection.h"
 
-class PrefService;
+class PrefServiceSimple;
 
 // This interface is used to access and mutate the preferences related to
 // desktop notifications.
 class NotificationPrefsManager {
  public:
   virtual ~NotificationPrefsManager() {}
 
   // Registers preferences.
-  static void RegisterPrefs(PrefService* prefs);
+  static void RegisterPrefs(PrefServiceSimple* prefs);
 
   // Gets the preference indicating where notifications should be placed.
   virtual BalloonCollection::PositionPreference
       GetPositionPreference() const = 0;
 
   // Sets the preference that indicates where notifications should
   // be placed on the screen.
   virtual void SetPositionPreference(
       BalloonCollection::PositionPreference preference) = 0;
 
  protected:
   NotificationPrefsManager() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NotificationPrefsManager);
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_PREFS_MANAGER_H_