Split PrefService into PrefService, PrefServiceSimple and PrefServiceSyncable.

chrome/browser/web_resource/plugins_resource_service.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_WEB_RESOURCE_PLUGINS_RESOURCE_SERVICE_H_
 #define CHROME_BROWSER_WEB_RESOURCE_PLUGINS_RESOURCE_SERVICE_H_
 
 #include "chrome/browser/web_resource/web_resource_service.h"
 
+class PrefService;
+class PrefServiceSimple;
+
 // This resource service periodically fetches plug-in metadata
 // from a remote server and updates local state and PluginFinder.
 class PluginsResourceService : public WebResourceService {
  public:
   explicit PluginsResourceService(PrefService* local_state);
 
-  static void RegisterPrefs(PrefService* local_state);
+  static void RegisterPrefs(PrefServiceSimple* local_state);
 
  private:
   virtual ~PluginsResourceService();
 
   // WebResourceService override to process the parsed information.
   virtual void Unpack(const base::DictionaryValue& parsed_json) OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(PluginsResourceService);
 };
 
 #endif  // CHROME_BROWSER_WEB_RESOURCE_PLUGINS_RESOURCE_SERVICE_H_