[SyncFS] Make routines using metadata database async

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 87 matching lines @@
       const SyncStatusCallback& callback);
   void ProcessRemoteChange(const SyncFileCallback& callback);
   void SetRemoteChangeProcessor(
       RemoteChangeProcessorOnWorker* remote_change_processor_on_worker);
   RemoteServiceState GetCurrentState() const;
   void GetOriginStatusMap(
       const RemoteFileSyncService::StatusMapCallback& callback);
   scoped_ptr<base::ListValue> DumpFiles(const GURL& origin);
   scoped_ptr<base::ListValue> DumpDatabase();
   void SetSyncEnabled(bool enabled);
+  void PromoteDemotedChanges();
   SyncStatusCode SetDefaultConflictResolutionPolicy(
       ConflictResolutionPolicy policy);
   SyncStatusCode SetConflictResolutionPolicy(
       const GURL& origin,
       ConflictResolutionPolicy policy);
   ConflictResolutionPolicy GetDefaultConflictResolutionPolicy()
       const;
   ConflictResolutionPolicy GetConflictResolutionPolicy(
       const GURL& origin) const;
 
@@ skipping 12 matching lines @@
   void OnNetworkChanged(net::NetworkChangeNotifier::ConnectionType type);
 
   drive::DriveServiceInterface* GetDriveService();
   drive::DriveUploaderInterface* GetDriveUploader();
   MetadataDatabase* GetMetadataDatabase();
   SyncTaskManager* GetSyncTaskManager();
 
   void AddObserver(Observer* observer);
 
  private:
-  friend class DriveBackendSyncTest;
-  friend class SyncEngineTest;
-
   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_