Remove #pragma once from chrome/browser/policy

chrome/browser/policy/async_policy_loader.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_ASYNC_POLICY_LOADER_H_
 #define CHROME_BROWSER_POLICY_ASYNC_POLICY_LOADER_H_
-#pragma once
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time.h"
 
 namespace policy {
 
 class PolicyBundle;
 
@@ skipping 72 matching lines @@
   // wall clock times come from the same source, just in case there is some
   // non-local filesystem involved.
   base::Time last_modification_clock_;
 
   DISALLOW_COPY_AND_ASSIGN(AsyncPolicyLoader);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_ASYNC_POLICY_LOADER_H_