[SyncFS] Remove usage of file task runner under drive_backend/

chrome/browser/sync_file_system/drive_backend/local_to_remote_syncer.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_DRIVE_BACKEND_LOCAL_TO_REMOTE_SYNCER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_LOCAL_TO_REMOTE_SYNCER_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 58 matching lines @@
   void HandleExistingRemoteFile(scoped_ptr<SyncTaskToken> token);
 
   void UpdateTrackerForReusedFolder(const FileDetails& details,
                                     scoped_ptr<SyncTaskToken> token);
 
   void DeleteRemoteFile(scoped_ptr<SyncTaskToken> token);
   void DidDeleteRemoteFile(scoped_ptr<SyncTaskToken> token,
                            google_apis::GDataErrorCode error);
 
   void UploadExistingFile(scoped_ptr<SyncTaskToken> token);
-  void DidGetMD5ForUpload(scoped_ptr<SyncTaskToken> token,
-                          const std::string& local_file_md5);
   void DidUploadExistingFile(scoped_ptr<SyncTaskToken> token,
                              google_apis::GDataErrorCode error,
                              const GURL&,
                              scoped_ptr<google_apis::FileResource>);
   void DidUpdateDatabaseForUploadExistingFile(
       scoped_ptr<SyncTaskToken> token,
       SyncStatusCode status);
   void UpdateRemoteMetadata(const std::string& file_id,
                             scoped_ptr<SyncTaskToken> token);
   void DidGetRemoteMetadata(const std::string& file_id,
@@ skipping 39 matching lines @@
 
   base::WeakPtrFactory<LocalToRemoteSyncer> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalToRemoteSyncer);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_LOCAL_TO_REMOTE_SYNCER_H_