Introduce PrefRegistrySyncable, simplifying PrefServiceSyncable.

chrome/browser/content_settings/content_settings_pref_provider.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_CONTENT_SETTINGS_CONTENT_SETTINGS_PREF_PROVIDER_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_PREF_PROVIDER_H_
 
 // A content settings provider that takes its settings out of the pref service.
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/prefs/public/pref_change_registrar.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/content_settings/content_settings_observable_provider.h"
 #include "chrome/browser/content_settings/content_settings_origin_identifier_value_map.h"
 #include "chrome/browser/content_settings/content_settings_utils.h"
 
 class PrefService;
-class PrefServiceSyncable;
+class PrefRegistrySyncable;
 
 namespace base {
 class DictionaryValue;
 }
 
 namespace content_settings {
 
 // Content settings provider that provides content settings from the user
 // preference.
 class PrefProvider : public ObservableProvider {
  public:
-  static void RegisterUserPrefs(PrefServiceSyncable* prefs);
+  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
 
   PrefProvider(PrefService* prefs, bool incognito);
   virtual ~PrefProvider();
 
   // ProviderInterface implementations.
   virtual RuleIterator* GetRuleIterator(
       ContentSettingsType content_type,
       const ResourceIdentifier& resource_identifier,
       bool incognito) const OVERRIDE;
 
@@ skipping 58 matching lines @@
 
   // Used around accesses to the value map objects to guarantee thread safety.
   mutable base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefProvider);
 };
 
 }  // namespace content_settings
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_PREF_PROVIDER_H_