Make generateReferrerHeader() return a Referrer instead of a String

Source/core/loader/FrameFetchContext.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 55 matching lines @@
         if (request.httpReferrer().isNull()) {
             outgoingReferrer = document->outgoingReferrer();
             referrerPolicy = document->referrerPolicy();
             outgoingOrigin = document->outgoingOrigin();
         } else {
             outgoingReferrer = request.httpReferrer();
             referrerPolicy = request.referrerPolicy();
             outgoingOrigin = SecurityOrigin::createFromString(outgoingReferrer)->toString();
         }
 
-        outgoingReferrer = SecurityPolicy::generateReferrerHeader(referrerPolicy, request.url(), outgoingReferrer);
-        if (outgoingReferrer.isEmpty())
-            request.clearHTTPReferrer();
-        else
-            request.setHTTPReferrer(Referrer(outgoingReferrer, referrerPolicy));
-
+        request.setHTTPReferrer(SecurityPolicy::generateReferrer(referrerPolicy, request.url(), outgoingReferrer));
         request.addHTTPOriginIfNeeded(AtomicString(outgoingOrigin));
     }
 
     // The remaining modifications are only necessary for HTTP and HTTPS.
     if (!request.url().isEmpty() && !request.url().protocolIsInHTTPFamily())
         return;
 
     m_frame->loader().applyUserAgent(request);
 }
 
@@ skipping 117 matching lines @@
     dispatchDidFinishLoading(ensureLoader(loader), identifier, 0, 0);
 }
 
 void FrameFetchContext::trace(Visitor* visitor)
 {
     visitor->trace(m_frame);
     FetchContext::trace(visitor);
 }
 
 } // namespace blink