Upstream iOS web code.

ios/web/public/referrer.h

 // Copyright 2014 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 IOS_WEB_PUBLIC_REFERRER_H_
 #define IOS_WEB_PUBLIC_REFERRER_H_
 
 #include "base/logging.h"
 #include "url/gurl.h"
 
 namespace web {
 
 enum ReferrerPolicy {
   ReferrerPolicyAlways,
   ReferrerPolicyDefault,
+  ReferrerPolicyNoReferrerWhenDowngrade,
   ReferrerPolicyNever,
   ReferrerPolicyOrigin,
-  ReferrerPolicyLast = ReferrerPolicyOrigin
+  ReferrerPolicyOriginWhenCrossOrigin,
+  ReferrerPolicyLast = ReferrerPolicyOriginWhenCrossOrigin
 };
 
 // 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 Referrer {
   Referrer(const GURL& url, ReferrerPolicy policy) : url(url), policy(policy) {}
   Referrer() : policy(ReferrerPolicyDefault) {}
 
   GURL url;
   ReferrerPolicy policy;
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_PUBLIC_REFERRER_H_