Use base::MessageLoop in more files.

chrome/browser/sync/glue/history_model_worker.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/glue/history_model_worker.h"
 
 #include "base/memory/ref_counted.h"
 #include "base/message_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 30 matching lines @@
   syncer::SyncerError* error_;
 };
 
 class AddDBThreadObserverTask : public history::HistoryDBTask {
  public:
   AddDBThreadObserverTask(HistoryModelWorker* history_worker)
      : history_worker_(history_worker) {}
 
   virtual bool RunOnDBThread(history::HistoryBackend* backend,
                              history::HistoryDatabase* db) OVERRIDE {
-    MessageLoop::current()->AddDestructionObserver(history_worker_.get());
+    base::MessageLoop::current()->AddDestructionObserver(history_worker_.get());
     return true;
   }
 
   virtual void DoneRunOnMainThread() OVERRIDE {}
 
  private:
   virtual ~AddDBThreadObserverTask() {}
 
   scoped_refptr<HistoryModelWorker> history_worker_;
 };
@@ skipping 48 matching lines @@
   return error;
 }
 
 syncer::ModelSafeGroup HistoryModelWorker::GetModelSafeGroup() {
   return syncer::GROUP_HISTORY;
 }
 
 HistoryModelWorker::~HistoryModelWorker() {}
 
 }  // namespace browser_sync