Implement referrerpolicy attribute for anchor elements

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
  * License as published by the Free Software Foundation; either
@@ skipping 18 matching lines @@
 #include "core/events/MouseEvent.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/layout/LayoutImage.h"
 #include "core/loader/FrameLoadRequest.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "core/loader/PingLoader.h"
 #include "core/page/ChromeClient.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/network/NetworkHints.h"
+#include "platform/weborigin/SecurityPolicy.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 HTMLAnchorElement::HTMLAnchorElement(const QualifiedName& tagName, Document& document)
     : HTMLElement(tagName, document)
     , m_linkRelations(0)
     , m_cachedVisitedLinkHash(0)
     , m_wasFocusedByMouse(false)
@@ skipping 291 matching lines @@
     appendServerMapMousePosition(url, event);
     KURL completedURL = document().completeURL(url.toString());
 
     // Schedule the ping before the frame load. Prerender in Chrome may kill the renderer as soon as the navigation is
     // sent out.
     sendPings(completedURL);
 
     ResourceRequest request(completedURL);
     request.setUIStartTime(event->uiCreateTime());
     request.setInputPerfMetricReportPolicy(InputToLoadPerfMetricReportPolicy::ReportLink);
+
+    ReferrerPolicy policy;
+    if (RuntimeEnabledFeatures::referrerPolicyAttributeEnabled() && hasAttribute(referrerpolicyAttr) && SecurityPolicy::referrerPolicyFromString(fastGetAttribute(referrerpolicyAttr), &policy) && !hasRel(RelationNoReferrer)) {
+        request.setHTTPReferrer(SecurityPolicy::generateReferrer(policy, completedURL, document().outgoingReferrer()));
+    }
+
     if (hasAttribute(downloadAttr)) {
         request.setRequestContext(WebURLRequest::RequestContextDownload);
         bool isSameOrigin = completedURL.protocolIsData() || document().securityOrigin()->canRequest(completedURL);
         const AtomicString& suggestedName = (isSameOrigin ? fastGetAttribute(downloadAttr) : nullAtom);
 
         frame->loader().client()->loadURLExternally(request, NavigationPolicyDownload, suggestedName);
     } else {
         request.setRequestContext(WebURLRequest::RequestContextHyperlink);
         FrameLoadRequest frameRequest(&document(), request, getAttribute(targetAttr));
         frameRequest.setTriggeringEvent(event);
@@ skipping 31 matching lines @@
             Vector<String> argv;
             argv.append("a");
             argv.append(fastGetAttribute(hrefAttr));
             activityLogger->logEvent("blinkAddElement", argv.size(), argv.data());
         }
     }
     return HTMLElement::insertedInto(insertionPoint);
 }
 
 } // namespace blink