[Sync] Put everything in sync/api into csync namespace

chrome/browser/sync/glue/extension_setting_data_type_controller.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_SYNC_GLUE_EXTENSION_SETTING_DATA_TYPE_CONTROLLER_H__
 #define CHROME_BROWSER_SYNC_GLUE_EXTENSION_SETTING_DATA_TYPE_CONTROLLER_H__
 #pragma once
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "chrome/browser/sync/glue/new_non_frontend_data_type_controller.h"
 
 class Profile;
 class ProfileSyncComponentsFactory;
 class ProfileSyncService;
+
+namespace csync {
 class SyncableService;
+}
 
 namespace extensions {
 class SettingsFrontend;
 }
 
 namespace browser_sync {
 
 class ExtensionSettingDataTypeController
     : public NewNonFrontendDataTypeController {
  public:
@@ skipping 23 matching lines @@
   // These only used on the UI thread.
   Profile* profile_;
   ProfileSyncService* profile_sync_service_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionSettingDataTypeController);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_EXTENSION_SETTING_DATA_TYPE_CONTROLLER_H__