Make generateReferrerHeader() return a Referrer instead of a String

Source/platform/network/ResourceRequest.h

 /*
  * Copyright (C) 2003, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  * Copyright (C) 2009, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 95 matching lines @@
     void addHTTPHeaderFields(const HTTPHeaderMap& headerFields);
     void clearHTTPHeaderField(const AtomicString& name);
 
     void clearHTTPAuthorization();
 
     const AtomicString& httpContentType() const { return httpHeaderField("Content-Type");  }
     void setHTTPContentType(const AtomicString& httpContentType) { setHTTPHeaderField("Content-Type", httpContentType); }
 
     const AtomicString& httpReferrer() const { return httpHeaderField("Referer"); }
     ReferrerPolicy referrerPolicy() const { return m_referrerPolicy; }
-    void setHTTPReferrer(const Referrer& httpReferrer) { setHTTPHeaderField("Referer", httpReferrer.referrer); m_referrerPolicy = httpReferrer.referrerPolicy; }
+    void setHTTPReferrer(const Referrer&);
     void clearHTTPReferrer();
 
     const AtomicString& httpOrigin() const { return httpHeaderField("Origin"); }
     void setHTTPOrigin(const AtomicString& httpOrigin) { setHTTPHeaderField("Origin", httpOrigin); }
     void clearHTTPOrigin();
     void addHTTPOriginIfNeeded(const AtomicString& origin);
 
     const AtomicString& httpUserAgent() const { return httpHeaderField("User-Agent"); }
     void setHTTPUserAgent(const AtomicString& httpUserAgent) { setHTTPHeaderField("User-Agent", httpUserAgent); }
     void clearHTTPUserAgent();
@@ skipping 141 matching lines @@
     blink::WebURLRequest::FetchRequestMode m_fetchRequestMode;
     blink::WebURLRequest::FetchCredentialsMode m_fetchCredentialsMode;
     ReferrerPolicy m_referrerPolicy;
 };
 
 unsigned initializeMaximumHTTPConnectionCountPerHost();
 
 } // namespace blink
 
 #endif // ResourceRequest_h