[SyncFS] Construct and destruct sync_worker in worker_task_runner

chrome/browser/sync_file_system/drive_backend/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_SYNC_WORKER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_WORKER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 55 matching lines @@
                                      SyncFileStatus file_status,
                                      SyncAction sync_action,
                                      SyncDirection direction) = 0;
     virtual void UpdateServiceState(RemoteServiceState state,
                                     const std::string& description) = 0;
 
    protected:
     virtual ~Observer() {}
   };
 
-  static scoped_ptr<SyncWorker> CreateOnWorker(
-      const base::FilePath& base_dir,
-      Observer* observer,
-      const base::WeakPtr<ExtensionServiceInterface>& extension_service,
-      scoped_ptr<SyncEngineContext> sync_engine_context,
-      leveldb::Env* env_override);
+  SyncWorker(const base::FilePath& base_dir,
+             const base::WeakPtr<ExtensionServiceInterface>& extension_service,
+             scoped_ptr<SyncEngineContext> sync_engine_context,
+             leveldb::Env* env_override);
 
   virtual ~SyncWorker();
 
   void Initialize();
 
   // SyncTaskManager::Client overrides
   virtual void MaybeScheduleNextTask() OVERRIDE;
   virtual void NotifyLastOperationStatus(
       SyncStatusCode sync_status, bool used_network) OVERRIDE;
 
@@ skipping 41 matching lines @@
   drive::DriveUploaderInterface* GetDriveUploader();
   MetadataDatabase* GetMetadataDatabase();
   SyncTaskManager* GetSyncTaskManager();
 
   void AddObserver(Observer* observer);
 
  private:
   friend class DriveBackendSyncTest;
   friend class SyncEngineTest;
 
-  SyncWorker(const base::FilePath& base_dir,
-             const base::WeakPtr<ExtensionServiceInterface>& extension_service,
-             scoped_ptr<SyncEngineContext> sync_engine_context,
-             leveldb::Env* env_override);
-
   void DoDisableApp(const std::string& app_id,
                     const SyncStatusCallback& callback);
   void DoEnableApp(const std::string& app_id,
                    const SyncStatusCallback& callback);
 
   void PostInitializeTask();
   void DidInitialize(SyncEngineInitializer* initializer,
                      SyncStatusCode status);
   void UpdateRegisteredApp();
   void DidQueryAppStatus(const AppStatusMap* app_status);
@@ skipping 38 matching lines @@
   ObserverList<Observer> observers_;
 
   base::WeakPtrFactory<SyncWorker> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(SyncWorker);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_WORKER_H_