Revert of [SyncFS] Post tasks between SyncEngine and SyncWorker

chrome/browser/sync_file_system/drive_backend/sync_engine.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_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_ENGINE_H_
 
 #include <set>
 #include <string>
 
@@ skipping 44 matching lines @@
  public:
   typedef Observer SyncServiceObserver;
 
   static scoped_ptr<SyncEngine> CreateForBrowserContext(
       content::BrowserContext* context);
   static void AppendDependsOnFactories(
       std::set<BrowserContextKeyedServiceFactory*>* factories);
 
   virtual ~SyncEngine();
 
-  void Initialize(const base::FilePath& base_dir,
-                  base::SequencedTaskRunner* file_task_runner,
-                  leveldb::Env* env_override);
+  void Initialize(
+      const base::FilePath& base_dir,
+      base::SequencedTaskRunner* task_runner,
+      leveldb::Env* env_override);
 
   // RemoteFileSyncService overrides.
   virtual void AddServiceObserver(SyncServiceObserver* observer) OVERRIDE;
   virtual void AddFileStatusObserver(FileStatusObserver* observer) OVERRIDE;
   virtual void RegisterOrigin(
       const GURL& origin,
       const SyncStatusCallback& callback) OVERRIDE;
   virtual void EnableOrigin(
       const GURL& origin,
       const SyncStatusCallback& callback) OVERRIDE;
@@ skipping 61 matching lines @@
   void UpdateSyncEnabled(bool enabled);
 
  private:
   friend class DriveBackendSyncTest;
   friend class SyncEngineTest;
   // TODO(peria): Remove friendship with SyncWorker
   friend class SyncWorker;
 
   SyncEngine(scoped_ptr<drive::DriveServiceInterface> drive_service,
              scoped_ptr<drive::DriveUploaderInterface> drive_uploader,
-             base::SequencedTaskRunner* worker_task_runner,
              drive::DriveNotificationManager* notification_manager,
              ExtensionServiceInterface* extension_service,
              SigninManagerBase* signin_manager);
 
   void DidProcessRemoteChange(RemoteToLocalSyncer* syncer);
   void DidApplyLocalChange(LocalToRemoteSyncer* syncer,
                            SyncStatusCode status);
   void UpdateServiceState(const std::string& description);
   void UpdateRegisteredApps();
   void NotifyLastOperationStatus();
 
   scoped_ptr<drive::DriveServiceInterface> drive_service_;
   scoped_ptr<drive::DriveUploaderInterface> drive_uploader_;
 
   // These external services are not owned by SyncEngine.
   // The owner of the SyncEngine is responsible for their lifetime.
   // I.e. the owner should declare the dependency explicitly by calling
   // KeyedService::DependsOn().
   drive::DriveNotificationManager* notification_manager_;
   ExtensionServiceInterface* extension_service_;
   SigninManagerBase* signin_manager_;
 
   ObserverList<SyncServiceObserver> service_observers_;
   ObserverList<FileStatusObserver> file_status_observers_;
 
   scoped_ptr<SyncWorker> sync_worker_;
-  scoped_refptr<base::SequencedTaskRunner> worker_task_runner_;
 
   base::WeakPtrFactory<SyncEngine> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(SyncEngine);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_ENGINE_H_