[SyncFS] Drop PostTaskAndReply from LocalToRemoteSyncer (5)

chrome/browser/sync_file_system/drive_backend/local_to_remote_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/local_to_remote_syncer.h"
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/format_macros.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/sequenced_task_runner.h"
 #include "base/strings/stringprintf.h"
 #include "base/task_runner_util.h"
 #include "chrome/browser/drive/drive_api_util.h"
 #include "chrome/browser/drive/drive_service_interface.h"
 #include "chrome/browser/drive/drive_uploader.h"
+#include "chrome/browser/sync_file_system/drive_backend/callback_helper.h"
 #include "chrome/browser/sync_file_system/drive_backend/drive_backend_util.h"
 #include "chrome/browser/sync_file_system/drive_backend/folder_creator.h"
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.h"
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.pb.h"
 #include "chrome/browser/sync_file_system/drive_backend/sync_engine_context.h"
 #include "chrome/browser/sync_file_system/drive_backend/sync_task_manager.h"
 #include "chrome/browser/sync_file_system/drive_backend/sync_task_token.h"
 #include "chrome/browser/sync_file_system/logger.h"
 #include "google_apis/drive/drive_api_parser.h"
 #include "webkit/common/fileapi/file_system_util.h"
@@ skipping 358 matching lines @@
         remote_file_tracker_->file_id(), callback);
     return;
   }
   callback.Run(SYNC_STATUS_OK);
 }
 
 void LocalToRemoteSyncer::UploadExistingFile(
     const SyncStatusCallback& callback)  {
   DCHECK(remote_file_tracker_);
   DCHECK(remote_file_tracker_->has_synced_details());
+  DCHECK(sync_context_->GetWorkerTaskRunner()->RunsTasksOnCurrentThread());
 
-  base::PostTaskAndReplyWithResult(
-      sync_context_->GetFileTaskRunner(), FROM_HERE,
-      base::Bind(&drive::util::GetMd5Digest, local_path_),
+  base::Callback<void(const std::string&)> did_calculate_callback =
       base::Bind(&LocalToRemoteSyncer::DidGetMD5ForUpload,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback));
+                 weak_ptr_factory_.GetWeakPtr(), callback);
+
+  sync_context_->GetWorkerTaskRunner()->PostTask(
+      FROM_HERE,
+      CreateComposedFunction(
+          base::Bind(&drive::util::GetMd5Digest, local_path_),
+          RelayCallbackToTaskRunner(
+              sync_context_->GetWorkerTaskRunner(), FROM_HERE,
+              did_calculate_callback)));
 }
 
 void LocalToRemoteSyncer::DidGetMD5ForUpload(
     const SyncStatusCallback& callback,
     const std::string& local_file_md5) {
   if (local_file_md5 == remote_file_tracker_->synced_details().md5()) {
     // Local file is not changed.
     callback.Run(SYNC_STATUS_OK);
     return;
   }
@@ skipping 282 matching lines @@
   set_used_network(true);
   return sync_context_->GetDriveUploader();
 }
 
 MetadataDatabase* LocalToRemoteSyncer::metadata_database() {
   return sync_context_->GetMetadataDatabase();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system