[SyncFS] Fix unexpected delay on running sync task

chrome/browser/sync_file_system/drive_backend/sync_worker.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_worker.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "chrome/browser/drive/drive_service_interface.h"
@@ skipping 374 matching lines @@
     return;
   }
   if (status != SYNC_STATUS_OK) {
     UpdateServiceState(REMOTE_SERVICE_TEMPORARY_UNAVAILABLE,
                        "Could not initialize remote service");
     return;
   }
 
   scoped_ptr<MetadataDatabase> metadata_database =
       initializer->PassMetadataDatabase();
-  if (metadata_database)
+  if (metadata_database) {
     context_->SetMetadataDatabase(metadata_database.Pass());
+    return;
+  }
 
+  UpdateServiceState(REMOTE_SERVICE_OK, std::string());
   UpdateRegisteredApps();
 }
 
 void SyncWorker::UpdateRegisteredApps() {
   MetadataDatabase* metadata_db = GetMetadataDatabase();
   DCHECK(sequence_checker_.CalledOnValidSequencedThread());
   DCHECK(metadata_db);
 
   scoped_ptr<std::vector<std::string> > app_ids(new std::vector<std::string>);
   metadata_db->GetRegisteredAppIDs(app_ids.get());
@@ skipping 300 matching lines @@
   return context_->GetDriveUploader();
 }
 
 MetadataDatabase* SyncWorker::GetMetadataDatabase() {
   DCHECK(sequence_checker_.CalledOnValidSequencedThread());
   return context_->GetMetadataDatabase();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system