Remove #pragma once from sync

sync/engine/syncer_proto_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.
 
 #ifndef SYNC_ENGINE_SYNCER_PROTO_UTIL_H_
 #define SYNC_ENGINE_SYNCER_PROTO_UTIL_H_
-#pragma once
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
 #include "base/time.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/util/syncer_error.h"
 #include "sync/sessions/sync_session.h"
 #include "sync/syncable/blob.h"
 
@@ skipping 113 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, VerifyResponseBirthday);
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, HandleThrottlingNoDatatypes);
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, HandleThrottlingWithDatatypes);
 
   DISALLOW_COPY_AND_ASSIGN(SyncerProtoUtil);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_SYNCER_PROTO_UTIL_H_