Pass blocking pool runner to CreateTemporaryFile in SyncFS v2 drive_backend

chrome/browser/sync_file_system/drive_backend/remote_to_local_syncer.cc

 // 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.
 
 #include "chrome/browser/sync_file_system/drive_backend/remote_to_local_syncer.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 560 matching lines @@
   remote_change_processor()->ApplyRemoteChange(
       FileChange(FileChange::FILE_CHANGE_DELETE, SYNC_FILE_TYPE_UNKNOWN),
       base::FilePath(),
       url_,
       callback);
 }
 
 void RemoteToLocalSyncer::DownloadFile(const SyncStatusCallback& callback) {
   base::PostTaskAndReplyWithResult(
       sync_context_->GetBlockingTaskRunner(), FROM_HERE,
-      base::Bind(&sync_file_system::drive_backend::CreateTemporaryFile),
+      base::Bind(&sync_file_system::drive_backend::CreateTemporaryFile,
+                 make_scoped_refptr(sync_context_->GetBlockingTaskRunner())),
       base::Bind(&RemoteToLocalSyncer::DidCreateTemporaryFileForDownload,
                  weak_ptr_factory_.GetWeakPtr(), callback));
 }
 
 void RemoteToLocalSyncer::DidCreateTemporaryFileForDownload(
     const SyncStatusCallback& callback,
     webkit_blob::ScopedFile file) {
   base::FilePath path = file.path();
   drive_service()->DownloadFile(
       path, remote_metadata_->file_id(),
@@ skipping 72 matching lines @@
   return sync_context_->GetMetadataDatabase();
 }
 
 RemoteChangeProcessor* RemoteToLocalSyncer::remote_change_processor() {
   DCHECK(sync_context_->GetRemoteChangeProcessor());
   return sync_context_->GetRemoteChangeProcessor();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system