Revert of [SyncFS] Post tasks between SyncEngine and SyncWorker

chrome/browser/sync_file_system/drive_backend/sync_engine_context.cc

 // 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.
 
 #include "chrome/browser/sync_file_system/drive_backend/sync_engine_context.h"
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/sequenced_task_runner.h"
 #include "chrome/browser/drive/drive_service_interface.h"
 #include "chrome/browser/drive/drive_uploader.h"
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.h"
 #include "chrome/browser/sync_file_system/remote_change_processor.h"
 
 namespace sync_file_system {
 namespace drive_backend {
 
 SyncEngineContext::SyncEngineContext(
     drive::DriveServiceInterface* drive_service,
     drive::DriveUploaderInterface* drive_uploader,
-    base::SequencedTaskRunner* ui_task_runner,
-    base::SequencedTaskRunner* file_task_runner)
+    base::SequencedTaskRunner* task_runner)
     : drive_service_(drive_service),
       drive_uploader_(drive_uploader),
       remote_change_processor_(NULL),
-      ui_task_runner_(ui_task_runner),
-      file_task_runner_(file_task_runner) {}
+      task_runner_(task_runner) {}
 
 SyncEngineContext::~SyncEngineContext() {}
 
 drive::DriveServiceInterface* SyncEngineContext::GetDriveService() {
   return drive_service_;
 }
 
 drive::DriveUploaderInterface* SyncEngineContext::GetDriveUploader() {
   return drive_uploader_;
 }
 
 MetadataDatabase* SyncEngineContext::GetMetadataDatabase() {
   return metadata_database_.get();
 }
 
 scoped_ptr<MetadataDatabase> SyncEngineContext::PassMetadataDatabase() {
   return metadata_database_.Pass();
 }
 
 RemoteChangeProcessor* SyncEngineContext::GetRemoteChangeProcessor() {
   return remote_change_processor_;
 }
 
-base::SequencedTaskRunner* SyncEngineContext::GetUiTaskRunner() {
-  return ui_task_runner_.get();
-}
-
-base::SequencedTaskRunner* SyncEngineContext::GetFileTaskRunner() {
-  return file_task_runner_.get();
+base::SequencedTaskRunner* SyncEngineContext::GetBlockingTaskRunner() {
+  return task_runner_.get();
 }
 
 void SyncEngineContext::SetMetadataDatabase(
     scoped_ptr<MetadataDatabase> metadata_database) {
   if (metadata_database)
     metadata_database_ = metadata_database.Pass();
 }
 
 void SyncEngineContext::SetRemoteChangeProcessor(
     RemoteChangeProcessor* remote_change_processor) {
   remote_change_processor_ = remote_change_processor;
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system