Introduce PrefRegistrySyncable, simplifying PrefServiceSyncable.

chrome/browser/bookmarks/bookmark_prompt_prefs.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_BOOKMARKS_BOOKMARK_PROMPT_PREFS_H_
 #define CHROME_BROWSER_BOOKMARKS_BOOKMARK_PROMPT_PREFS_H_
 
 #include "base/basictypes.h"
 
-class PrefServiceSyncable;
+class PrefRegistrySyncable;
 class PrefServiceBase;
 
 // Helper class for getting, changing bookmark prompt related preferences.
 class BookmarkPromptPrefs {
  public:
   // Constructs and associates to |prefs|. Further operations occurred on
   // associated |prefs|.
   explicit BookmarkPromptPrefs(PrefServiceBase* prefs);
   ~BookmarkPromptPrefs();
 
   // Disables bookmark prompt feature.
   void DisableBookmarkPrompt();
 
   // Returns number of times bookmark prompt displayed so far.
   int GetPromptImpressionCount() const;
 
   // Increments bookmark prompt impression counter.
   void IncrementPromptImpressionCount();
 
   // Returns true if bookmark prompt feature enabled, otherwise false.
   bool IsBookmarkPromptEnabled() const;
 
   // Registers user preferences used by bookmark prompt feature.
-  static void RegisterUserPrefs(PrefServiceSyncable* prefs);
+  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
 
  private:
   PrefServiceBase* prefs_;  // Weak.
 
   DISALLOW_COPY_AND_ASSIGN(BookmarkPromptPrefs);
 };
 
 #endif  // CHROME_BROWSER_BOOKMARKS_BOOKMARK_PROMPT_PREFS_H_