Add UseCounters for referrerpolicy attributes

third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 398 matching lines @@
   request.setUIStartTime(
       (event->platformTimeStamp() - TimeTicks()).InSecondsF());
   request.setInputPerfMetricReportPolicy(
       InputToLoadPerfMetricReportPolicy::ReportLink);
 
   ReferrerPolicy policy;
   if (hasAttribute(referrerpolicyAttr) &&
       SecurityPolicy::referrerPolicyFromStringWithLegacyKeywords(
           fastGetAttribute(referrerpolicyAttr), &policy) &&
       !hasRel(RelationNoReferrer)) {
+    UseCounter::count(document(),
+                      UseCounter::HTMLAnchorElementReferrerPolicyAttribute);
     request.setHTTPReferrer(SecurityPolicy::generateReferrer(
         policy, completedURL, document().outgoingReferrer()));
   }
 
   if (hasAttribute(downloadAttr)) {
     request.setRequestContext(WebURLRequest::RequestContextDownload);
     bool isSameOrigin =
         completedURL.protocolIsData() ||
         document().getSecurityOrigin()->canRequest(completedURL);
     const AtomicString& suggestedName =
@@ skipping 52 matching lines @@
 }
 
 HTMLAnchorElement::NavigationHintSender*
 HTMLAnchorElement::ensureNavigationHintSender() {
   if (!m_navigationHintSender)
     m_navigationHintSender = NavigationHintSender::create(this);
   return m_navigationHintSender;
 }
 
 }  // namespace blink