Introduce PrefRegistrySyncable, simplifying PrefServiceSyncable.

chrome/browser/sync/profile_sync_components_factory_impl.cc

 // 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.
 
 #include "base/command_line.h"
 #include "build/build_config.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "chrome/browser/extensions/api/storage/settings_frontend.h"
 #include "chrome/browser/extensions/app_notification_manager.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/extension_system_factory.h"
 #include "chrome/browser/history/history_service.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/prefs/pref_model_associator.h"
-#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/prefs/pref_service_syncable.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search_engines/template_url_service.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/browser/signin/signin_manager.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/browser/spellchecker/spellcheck_factory.h"
 #include "chrome/browser/spellchecker/spellcheck_service.h"
 #include "chrome/browser/sync/glue/app_notification_data_type_controller.h"
 #include "chrome/browser/sync/glue/autofill_data_type_controller.h"
 #include "chrome/browser/sync/glue/autofill_profile_data_type_controller.h"
@@ skipping 251 matching lines @@
   return new SharedChangeProcessor();
 }
 
 base::WeakPtr<syncer::SyncableService> ProfileSyncComponentsFactoryImpl::
     GetSyncableServiceForType(syncer::ModelType type) {
   if (!profile_) {  // For tests.
      return base::WeakPtr<syncer::SyncableService>();
   }
   switch (type) {
     case syncer::PREFERENCES:
-      return profile_->GetPrefs()->GetSyncableService()->AsWeakPtr();
+      return PrefServiceSyncable::FromProfile(
+          profile_)->GetSyncableService()->AsWeakPtr();
     case syncer::AUTOFILL:
     case syncer::AUTOFILL_PROFILE: {
       if (!web_data_service_.get())
         return base::WeakPtr<syncer::SyncableService>();
       if (type == syncer::AUTOFILL) {
         return web_data_service_->GetAutocompleteSyncableService()->AsWeakPtr();
       } else {
         return web_data_service_->
                    GetAutofillProfileSyncableService()->AsWeakPtr();
       }
@@ skipping 96 matching lines @@
 ProfileSyncComponentsFactory::SyncComponents
     ProfileSyncComponentsFactoryImpl::CreateSessionSyncComponents(
        ProfileSyncService* profile_sync_service,
         DataTypeErrorHandler* error_handler) {
   SessionModelAssociator* model_associator =
       new SessionModelAssociator(profile_sync_service, error_handler);
   SessionChangeProcessor* change_processor =
       new SessionChangeProcessor(error_handler, model_associator);
   return SyncComponents(model_associator, change_processor);
 }