Introduce NavigationSimulator to use in unit tests

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_
 
 #include "base/logging.h"
 #include "content/common/content_export.h"
+#include "net/url_request/url_request.h"
 #include "third_party/WebKit/public/platform/WebReferrerPolicy.h"
 #include "url/gurl.h"
 
-namespace net {
-class URLRequest;
-}
-
 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, blink::WebReferrerPolicy policy)
       : url(url), policy(policy) {}
   Referrer() : policy(blink::WebReferrerPolicyDefault) {}
 
   GURL url;
   blink::WebReferrerPolicy policy;
 
   static Referrer SanitizeForRequest(const GURL& request,
                                      const Referrer& referrer);
 
   static void SetReferrerForRequest(net::URLRequest* request,
                                     const Referrer& referrer);
+
+  static net::URLRequest::ReferrerPolicy ReferrerPolicyForUrlRequest(
+      const Referrer& referrer);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_REFERRER_H_