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

chrome/browser/sync_file_system/drive_backend/fake_sync_worker.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_FAKE_SYNC_WORKER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_FAKE_SYNC_WORKER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 55 matching lines @@
   virtual void ProcessRemoteChange(const SyncFileCallback& callback) OVERRIDE;
   virtual void SetRemoteChangeProcessor(
       RemoteChangeProcessorOnWorker* remote_change_processor_on_worker)
       OVERRIDE;
   virtual RemoteServiceState GetCurrentState() const OVERRIDE;
   virtual void GetOriginStatusMap(
       const RemoteFileSyncService::StatusMapCallback& callback) OVERRIDE;
   virtual scoped_ptr<base::ListValue> DumpFiles(const GURL& origin) OVERRIDE;
   virtual scoped_ptr<base::ListValue> DumpDatabase() OVERRIDE;
   virtual void SetSyncEnabled(bool enabled) OVERRIDE;
-  virtual void PromoteDemotedChanges() OVERRIDE;
+  virtual void PromoteDemotedChanges(const base::Closure& callback) OVERRIDE;
   virtual void ApplyLocalChange(
       const FileChange& local_change,
       const base::FilePath& local_path,
       const SyncFileMetadata& local_metadata,
       const fileapi::FileSystemURL& url,
       const SyncStatusCallback& callback) OVERRIDE;
   virtual void OnNotificationReceived() OVERRIDE;
   virtual void OnReadyToSendRequests() OVERRIDE;
   virtual void OnRefreshTokenInvalid() OVERRIDE;
   virtual void OnNetworkChanged(
@@ skipping 28 matching lines @@
   ObserverList<Observer> observers_;
   base::SequenceChecker sequence_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeSyncWorker);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_FAKE_SYNC_WORKER_H_