Make img referrerpolicy attribute runtime-enabled

Source/core/html/parser/HTMLPreloadScanner.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
  * Copyright (C) 2010 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.
@@ skipping 180 matching lines @@
         if (pictureData.picked) {
             sourceSizeSet = pictureData.sourceSizeSet;
             sourceSize = pictureData.sourceSize;
         }
         if (sourceSizeSet) {
             resourceWidth.width = sourceSize;
             resourceWidth.isSet = true;
         }
 
         // The element's 'referrerpolicy' attribute (if present) takes precedence over the document's referrer policy.
-        ReferrerPolicy referrerPolicy = m_referrerPolicy != ReferrerPolicyDefault ? m_referrerPolicy : documentReferrerPolicy;
+        ReferrerPolicy referrerPolicy = (m_referrerPolicy != ReferrerPolicyDefault && RuntimeEnabledFeatures::referrerPolicyAttributeEnabled()) ? m_referrerPolicy : documentReferrerPolicy;
         OwnPtr<PreloadRequest> request = PreloadRequest::create(initiatorFor(m_tagImpl), position, m_urlToLoad, predictedBaseURL, resourceType(), referrerPolicy, resourceWidth, clientHintsPreferences, requestType);
         if (isCORSEnabled())
             request->setCrossOriginEnabled(allowStoredCredentials());
         request->setCharset(charset());
         request->setDefer(m_defer);
         return request.release();
     }
 
 private:
     template<typename NameType>
@@ skipping 22 matching lines @@
             m_srcsetAttributeValue = attributeValue;
             m_srcsetImageCandidate = bestFitSourceForSrcsetAttribute(m_mediaValues->devicePixelRatio(), m_sourceSize, attributeValue);
             setUrlToLoad(bestFitSourceForImageAttributes(m_mediaValues->devicePixelRatio(), m_sourceSize, m_imgSrcUrl, m_srcsetImageCandidate), AllowURLReplacement);
         } else if (match(attributeName, sizesAttr) && !m_sourceSizeSet) {
             m_sourceSize = SizesAttributeParser(m_mediaValues, attributeValue).length();
             m_sourceSizeSet = true;
             if (!m_srcsetImageCandidate.isEmpty()) {
                 m_srcsetImageCandidate = bestFitSourceForSrcsetAttribute(m_mediaValues->devicePixelRatio(), m_sourceSize, m_srcsetAttributeValue);
                 setUrlToLoad(bestFitSourceForImageAttributes(m_mediaValues->devicePixelRatio(), m_sourceSize, m_imgSrcUrl, m_srcsetImageCandidate), AllowURLReplacement);
             }
-        } else if (!m_referrerPolicySet && match(attributeName, referrerpolicyAttr) && !attributeValue.isNull()) {
+        } else if (!m_referrerPolicySet && RuntimeEnabledFeatures::referrerPolicyAttributeEnabled() && match(attributeName, referrerpolicyAttr) && !attributeValue.isNull()) {
             m_referrerPolicySet = true;
             SecurityPolicy::referrerPolicyFromString(attributeValue, &m_referrerPolicy);
         }
     }
 
     template<typename NameType>
     void processLinkAttribute(const NameType& attributeName, const String& attributeValue)
     {
         // FIXME - Don't set rel/media/crossorigin multiple times.
         if (match(attributeName, hrefAttr)) {
@@ skipping 415 matching lines @@
     else
         mediaValues = MediaValuesCached::create(*document);
     ASSERT(mediaValues->isSafeToSendToAnotherThread());
     defaultViewportMinWidth = document->viewportDefaultMinWidth();
     viewportMetaZeroValuesQuirk = document->settings() && document->settings()->viewportMetaZeroValuesQuirk();
     viewportMetaEnabled = document->settings() && document->settings()->viewportMetaEnabled();
     referrerPolicy = ReferrerPolicyDefault;
 }
 
 }