Remove #pragma once from ash

ash/test/ash_test_base.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 ASH_TEST_ASH_TEST_BASE_H_
 #define ASH_TEST_ASH_TEST_BASE_H_
-#pragma once
 
 #include <string>
 
 #include "ash/shell.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/views/test/test_views_delegate.h"
 
 namespace ash {
@@ skipping 35 matching lines @@
  private:
   MessageLoopForUI message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(AshTestBase);
 };
 
 }  // namespace test
 }  // namespace ash
 
 #endif  // ASH_TEST_ASH_TEST_BASE_H_