Remove #pragma once from sync

sync/engine/syncer_util.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.
 //
 // Utility functions manipulating syncable::Entries, intended for use by the
 // syncer.
 
 #ifndef SYNC_ENGINE_SYNCER_UTIL_H_
 #define SYNC_ENGINE_SYNCER_UTIL_H_
-#pragma once
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "sync/engine/syncer.h"
 #include "sync/engine/syncer_types.h"
 #include "sync/syncable/entry_kernel.h"
 #include "sync/syncable/metahandle_set.h"
 #include "sync/syncable/syncable_id.h"
@@ skipping 88 matching lines @@
     syncable::MetahandleSet* inserted_items,
     std::vector<syncable::Id>* commit_ids);
 
 void MarkDeletedChildrenSynced(
     syncable::Directory* dir,
     std::set<syncable::Id>* deleted_folders);
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_SYNCER_UTIL_H_