Remove #pragma once from chrome/browser/policy

chrome/browser/policy/device_management_service.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 CHROME_BROWSER_POLICY_DEVICE_MANAGEMENT_SERVICE_H_
 #define CHROME_BROWSER_POLICY_DEVICE_MANAGEMENT_SERVICE_H_
-#pragma once
 
 #include <deque>
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
@@ skipping 128 matching lines @@
 
   // Used to create tasks to run |Initialize| delayed on the UI thread.
   base::WeakPtrFactory<DeviceManagementService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceManagementService);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_DEVICE_MANAGEMENT_SERVICE_H_