[SyncFS] Add completion callback to PromoteDemotedChanges (1/3)

chrome/browser/sync_file_system/drive_backend/sync_worker_interface.h

 // Copyright 2014 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_FILE_SYSTEM_DRIVE_BACKEND_SYNC_WORKER_INTERFACE_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_WORKER_INTERFACE_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 67 matching lines @@
       const SyncStatusCallback& callback) = 0;
   virtual void ProcessRemoteChange(const SyncFileCallback& callback) = 0;
   virtual void SetRemoteChangeProcessor(
       RemoteChangeProcessorOnWorker* remote_change_processor_on_worker) = 0;
   virtual RemoteServiceState GetCurrentState() const = 0;
   virtual void GetOriginStatusMap(
       const RemoteFileSyncService::StatusMapCallback& callback) = 0;
   virtual scoped_ptr<base::ListValue> DumpFiles(const GURL& origin) = 0;
   virtual scoped_ptr<base::ListValue> DumpDatabase() = 0;
   virtual void SetSyncEnabled(bool enabled) = 0;
-  virtual void PromoteDemotedChanges() = 0;
+  virtual void PromoteDemotedChanges(const base::Closure& callback) = 0;
 
   // See LocalChangeProcessor for the details.
   virtual void ApplyLocalChange(
       const FileChange& local_change,
       const base::FilePath& local_path,
       const SyncFileMetadata& local_metadata,
       const fileapi::FileSystemURL& url,
       const SyncStatusCallback& callback) = 0;
 
   // See drive::DriveNotificationObserver for the details.
@@ skipping 17 matching lines @@
   // TODO(peria): Remove this interface after making FakeSyncWorker class.
   virtual void SetHasRefreshToken(bool has_refresh_token) = 0;
 
   DISALLOW_COPY_AND_ASSIGN(SyncWorkerInterface);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_WORKER_INTERFACE_H_