Remove #pragma once from sync

sync/api/syncable_service.h

 // 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.
 
 #ifndef SYNC_API_SYNCABLE_SERVICE_H_
 #define SYNC_API_SYNCABLE_SERVICE_H_
-#pragma once
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "sync/api/sync_change_processor.h"
 #include "sync/api/sync_data.h"
 #include "sync/api/sync_error.h"
 #include "sync/internal_api/public/base/model_type.h"
@@ skipping 42 matching lines @@
       const tracked_objects::Location& from_here,
       const SyncChangeList& change_list) OVERRIDE = 0;
 
  protected:
   virtual ~SyncableService();
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_API_SYNCABLE_SERVICE_H_