Remove #pragma once from sync

sync/engine/get_commit_ids_command.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_ENGINE_GET_COMMIT_IDS_COMMAND_H_
 #define SYNC_ENGINE_GET_COMMIT_IDS_COMMAND_H_
-#pragma once
 
 #include <utility>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "sync/engine/syncer_command.h"
 #include "sync/engine/syncer_util.h"
 #include "sync/sessions/ordered_commit_set.h"
 #include "sync/sessions/sync_session.h"
 #include "sync/syncable/directory.h"
@@ skipping 113 matching lines @@
 
   // Output parameter; see constructor comment.
   sessions::OrderedCommitSet* commit_set_;
 
   DISALLOW_COPY_AND_ASSIGN(GetCommitIdsCommand);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_GET_COMMIT_IDS_COMMAND_H_