Add a callback to RemoteFileSyncService for reporting errors.

chrome/browser/sync_file_system/sync_file_system_service.cc

 // Copyright (c) 2012 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/sync_file_system_service.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 38 matching lines @@
     const SyncStatusCallback& callback) {
   DCHECK(local_file_service_);
   DCHECK(app_origin == app_origin.GetOrigin());
 
   // TODO(kinuko,tzik): Instantiate the remote_file_service for the given
   // |service_name| if it hasn't been initialized.
 
   local_file_service_->MaybeInitializeFileSystemContext(
       app_origin, service_name, file_system_context, callback);
 
-  if (remote_file_service_)
-    remote_file_service_->RegisterOriginForTrackingChanges(app_origin);
+  if (remote_file_service_) {
+    // TODO(tzik): Handle errors in the completion callback.
+    remote_file_service_->RegisterOriginForTrackingChanges(
+        app_origin, fileapi::SyncStatusCallback());
+  }
 }
 
 void SyncFileSystemService::GetConflictFiles(
     const GURL& app_origin,
     const std::string& service_name,
     const fileapi::SyncFileSetCallback& callback) {
   DCHECK(app_origin == app_origin.GetOrigin());
 
   // TODO(kinuko): Implement.
   NOTIMPLEMENTED();
@@ skipping 74 matching lines @@
 
   scoped_ptr<RemoteFileSyncService> remote_file_service;
   // TODO(tzik): Instantiate DriveFileSyncService.
 
   service->Initialize(local_file_service.Pass(),
                       remote_file_service.Pass());
   return service;
 }
 
 }  // namespace sync_file_system