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

chrome/browser/sync_file_system/local/local_file_sync_service.h

 // Copyright 2013 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_LOCAL_LOCAL_FILE_SYNC_SERVICE_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_SYNC_SERVICE_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 105 matching lines @@
   // (crbug.com/324215), or deprecate the other if we keep doing so.
   void SetLocalChangeProcessorCallback(
       const GetLocalChangeProcessorCallback& get_local_change_processor);
 
   // Returns true via |callback| if the given file |url| has local pending
   // changes.
   void HasPendingLocalChanges(
       const fileapi::FileSystemURL& url,
       const HasPendingLocalChangeCallback& callback);
 
-  void PromoteDemotedChanges();
+  void PromoteDemotedChanges(const base::Closure& callback);
 
   // Returns the metadata of a remote file pointed by |url|.
   virtual void GetLocalFileMetadata(
       const fileapi::FileSystemURL& url,
       const SyncFileMetadataCallback& callback);
 
   // RemoteChangeProcessor overrides.
   virtual void PrepareForProcessRemoteChange(
       const fileapi::FileSystemURL& url,
       const PrepareChangeCallback& callback) OVERRIDE;
@@ skipping 114 matching lines @@
   GetLocalChangeProcessorCallback get_local_change_processor_;
 
   ObserverList<Observer> change_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalFileSyncService);
 };
 
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_SYNC_SERVICE_H_