Remove #pragma once from sync

sync/syncable/syncable_mock.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_SYNCABLE_SYNCABLE_MOCK_H_
 #define SYNC_SYNCABLE_SYNCABLE_MOCK_H_
-#pragma once
 
 #include <string>
 
 #include "sync/syncable/directory.h"
 #include "sync/syncable/write_transaction.h"
 #include "sync/test/fake_encryptor.h"
 #include "sync/test/null_directory_change_delegate.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 22 matching lines @@
 class MockSyncableWriteTransaction : public syncable::WriteTransaction {
  public:
   MockSyncableWriteTransaction(
       const tracked_objects::Location& from_here, Directory *directory);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // SYNC_SYNCABLE_SYNCABLE_MOCK_H_