Remove #pragma once from sync

sync/engine/syncer_types.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_TYPES_H_
 #define SYNC_ENGINE_SYNCER_TYPES_H_
-#pragma once
 
 // The intent of this is to keep all shared data types and enums for the syncer
 // in a single place without having dependencies between other files.
 namespace syncer {
 
 enum UpdateAttemptResponse {
   // Update was applied or safely ignored.
   SUCCESS,
 
   // The conditions described by the following enum values are not mutually
@@ skipping 60 matching lines @@
 };
 
 enum VerifyCommitResult {
   VERIFY_UNSYNCABLE,
   VERIFY_OK,
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_SYNCER_TYPES_H_