Remove #pragma once from content

content/public/common/referrer.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 CONTENT_PUBLIC_COMMON_REFERRER_H_
 #define CONTENT_PUBLIC_COMMON_REFERRER_H_
-#pragma once
 
 #include "content/common/content_export.h"
 #include "googleurl/src/gurl.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebReferrerPolicy.h"
 
 namespace content {
 
 // This struct holds a referrer URL, as well as the referrer policy to be
 // applied to this URL. When passing around referrers that will eventually end
 // up being used for URL requests, always use this struct.
 struct CONTENT_EXPORT Referrer {
   Referrer(const GURL& url, WebKit::WebReferrerPolicy policy) : url(url),
                                                                 policy(policy) {
   }
   Referrer() : policy(WebKit::WebReferrerPolicyDefault) {
   }
 
   GURL url;
   WebKit::WebReferrerPolicy policy;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_REFERRER_H_