[SyncFS] Post tasks between SyncEngine and SyncWorker

chrome/browser/sync_file_system/drive_backend/sync_engine_context.h

Index: chrome/browser/sync_file_system/drive_backend/sync_engine_context.h
diff --git a/chrome/browser/sync_file_system/drive_backend/sync_engine_context.h b/chrome/browser/sync_file_system/drive_backend/sync_engine_context.h
index e3e32d67e4722d2460872b58e440a91cb6383cc3..c80ead48b469be91356dca6d69273e4bb049db70 100644
--- a/chrome/browser/sync_file_system/drive_backend/sync_engine_context.h
+++ b/chrome/browser/sync_file_system/drive_backend/sync_engine_context.h
@@ -32,7 +32,8 @@ class SyncEngineContext {
   SyncEngineContext(
       drive::DriveServiceInterface* drive_service,
       drive::DriveUploaderInterface* drive_uploader,
-      base::SequencedTaskRunner* task_runner);
+      base::SequencedTaskRunner* worker_task_runner,
+      base::SequencedTaskRunner* ui_task_runner);
   ~SyncEngineContext();
 
   drive::DriveServiceInterface* GetDriveService();
@@ -40,6 +41,7 @@ class SyncEngineContext {
   MetadataDatabase* GetMetadataDatabase();
   RemoteChangeProcessor* GetRemoteChangeProcessor();
   base::SequencedTaskRunner* GetBlockingTaskRunner();
+  base::SequencedTaskRunner* GetUiTaskRunner();
 
   void SetMetadataDatabase(scoped_ptr<MetadataDatabase> metadata_database);
   void SetRemoteChangeProcessor(RemoteChangeProcessor* remote_change_processor);
@@ -52,7 +54,8 @@ class SyncEngineContext {
   RemoteChangeProcessor* remote_change_processor_;
 
   scoped_ptr<MetadataDatabase> metadata_database_;
-  scoped_refptr<base::SequencedTaskRunner> task_runner_;
+  scoped_refptr<base::SequencedTaskRunner> worker_task_runner_;
+  scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncEngineContext);
 };