Make generateReferrerHeader() return a Referrer instead of a String

Source/platform/weborigin/SecurityPolicy.h

 /*
  * Copyright (C) 2011 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 12 matching lines @@
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef SecurityPolicy_h
 #define SecurityPolicy_h
 
 #include "platform/PlatformExport.h"
+#include "platform/weborigin/Referrer.h"
 #include "platform/weborigin/ReferrerPolicy.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class KURL;
 class SecurityOrigin;
 
 class PLATFORM_EXPORT SecurityPolicy {
 public:
     // True if the referrer should be omitted according to the
     // ReferrerPolicyDefault. If you intend to send a referrer header, you
     // should use generateReferrerHeader instead.
     static bool shouldHideReferrer(const KURL&, const String& referrer);
 
     // Returns the referrer modified according to the referrer policy for a
     // navigation to a given URL. If the referrer returned is empty, the
     // referrer header should be omitted.
-    static String generateReferrerHeader(ReferrerPolicy, const KURL&, const String& referrer);
+    static Referrer generateReferrer(ReferrerPolicy, const KURL&, const String& referrer);
 
     static void addOriginAccessWhitelistEntry(const SecurityOrigin& sourceOrigin, const String& destinationProtocol, const String& destinationDomain, bool allowDestinationSubdomains);
     static void removeOriginAccessWhitelistEntry(const SecurityOrigin& sourceOrigin, const String& destinationProtocol, const String& destinationDomain, bool allowDestinationSubdomains);
     static void resetOriginAccessWhitelists();
 
     static bool isAccessWhiteListed(const SecurityOrigin* activeOrigin, const SecurityOrigin* targetOrigin);
     static bool isAccessToURLWhiteListed(const SecurityOrigin* activeOrigin, const KURL&);
 };
 
 } // namespace blink
 
 #endif // SecurityPolicy_h