[SyncFS] Remove using MessageLoop in worker thread

chrome/browser/sync_file_system/drive_backend/sync_engine_initializer.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_SYNC_ENGINE_INITIALIZER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_ENGINE_INITIALIZER_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
-#include "base/sequenced_task_runner.h"
 #include "chrome/browser/sync_file_system/drive_backend/sync_task.h"
 #include "chrome/browser/sync_file_system/sync_callbacks.h"
 #include "google_apis/drive/drive_common_callbacks.h"
 #include "google_apis/drive/gdata_errorcode.h"
 
 namespace drive {
 class DriveServiceInterface;
 }
 
 namespace google_apis {
@@ skipping 35 matching lines @@
 //  - Detach the remote sync-root folder from its parent if it has.
 //  - Fetch the folder contents of the remote sync-root folder.
 //    The contents are likely registered as app-root folders, but handle them
 //    as regular inactive folders until they are registered explicitly.
 //  - Populate database with the largest change ID, the sync-root folder and
 //    its contents.
 //
 class SyncEngineInitializer : public SyncTask {
  public:
   SyncEngineInitializer(SyncEngineContext* sync_context,
-                        base::SequencedTaskRunner* task_runner,
                         const base::FilePath& database_path,
                         leveldb::Env* env_override);
   virtual ~SyncEngineInitializer();
   virtual void RunPreflight(scoped_ptr<SyncTaskToken> token) OVERRIDE;
 
   scoped_ptr<MetadataDatabase> PassMetadataDatabase();
 
  private:
   typedef base::Callback<void(const SyncStatusCallback& callback)> Task;
 
@@ skipping 22 matching lines @@
       scoped_ptr<SyncTaskToken> token,
       google_apis::GDataErrorCode error,
       scoped_ptr<google_apis::ResourceList> resource_list);
   void PopulateDatabase(scoped_ptr<SyncTaskToken> token);
   void DidPopulateDatabase(scoped_ptr<SyncTaskToken> token,
                            SyncStatusCode status);
 
   SyncEngineContext* sync_context_;  // Not owned.
   leveldb::Env* env_override_;
 
-  scoped_refptr<base::SequencedTaskRunner> task_runner_;
   google_apis::CancelCallback cancel_callback_;
   base::FilePath database_path_;
 
   int find_sync_root_retry_count_;
 
   scoped_ptr<MetadataDatabase> metadata_database_;
   ScopedVector<google_apis::ResourceEntry> app_root_folders_;
 
   int64 largest_change_id_;
   std::string root_folder_id_;
 
   scoped_ptr<google_apis::ResourceEntry> sync_root_folder_;
 
   base::WeakPtrFactory<SyncEngineInitializer> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncEngineInitializer);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_ENGINE_INITIALIZER_H_