Avoid useless SYNC_CYCLE_CONTINUATION sync cycle

chrome/browser/sync/glue/ui_model_worker.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_BROWSER_SYNC_GLUE_UI_MODEL_WORKER_H_
 #define CHROME_BROWSER_SYNC_GLUE_UI_MODEL_WORKER_H_
 #pragma once
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
@@ skipping 19 matching lines @@
   UIModelWorker();
   virtual ~UIModelWorker();
 
   // Called by the UI thread on shutdown of the sync service. Blocks until
   // the UIModelWorker has safely met termination conditions, namely that
   // no task scheduled by CallDoWorkFromModelSafeThreadAndWait remains un-
   // processed and that syncapi will not schedule any further work for us to do.
   void Stop();
 
   // ModelSafeWorker implementation. Called on syncapi SyncerThread.
-  virtual UnrecoverableErrorInfo DoWorkAndWaitUntilDone(
+  virtual SyncerError DoWorkAndWaitUntilDone(
       const WorkCallback& work) OVERRIDE;
   virtual ModelSafeGroup GetModelSafeGroup() OVERRIDE;
 
   // Upon receiving this idempotent call, the ModelSafeWorker can
   // assume no work will ever be scheduled again from now on. If it has any work
   // that it has not yet completed, it must make sure to run it as soon as
   // possible as the Syncer is trying to shut down. Called from the CoreThread.
   void OnSyncerShutdownComplete();
 
   // Callback from |pending_work_| to notify us that it has been run.
@@ skipping 44 matching lines @@
   // SyncerThread has terminated. We only care about (1) when we are in Stop(),
   // because we have to manually Run() the task.
   base::ConditionVariable syncapi_event_;
 
   DISALLOW_COPY_AND_ASSIGN(UIModelWorker);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_UI_MODEL_WORKER_H_