Add ReferrerPolicy support to preload

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 61 matching lines @@
     // Log href attribute before logging resource fetching in process().
     logUpdateAttributeIfIsolatedWorldAndInDocument("link", hrefAttr, oldValue,
                                                    value);
     process();
   } else if (name == typeAttr) {
     m_type = value;
     process();
   } else if (name == asAttr) {
     m_as = value;
     process();
+  } else if (name == referrerpolicyAttr) {
+    m_referrerPolicy = value;

[Mike West, 2016/10/23 05:25:46]

Where do you take the page's referrer policy into account? Shouldn't the request
fall back to that policy if no policy is explicitly set for the element?

[Yoav Weiss, 2016/10/23 13:27:09]

It's done at the consumers of HTMLLinkElement::referrerPolicy() (so, inside
LinkLoader). Doing it here might be better when support is extended beyond just
preload.

   } else if (name == sizesAttr) {
     m_sizes->setValue(value);
   } else if (name == mediaAttr) {
     m_media = value.lower();
     process();
   } else if (name == scopeAttr) {
     m_scope = value;
     process();
   } else if (name == disabledAttr) {
     UseCounter::count(document(), UseCounter::HTMLLinkElementDisabled);
     if (LinkStyle* link = linkStyle())
       link->setDisabledState(!value.isNull());
   } else {
     if (name == titleAttr) {
       if (LinkStyle* link = linkStyle())
         link->setSheetTitle(value, StyleEngine::UpdateActiveSheets);
     }
 
     HTMLElement::parseAttribute(name, oldValue, value);
   }
 }
 
 bool HTMLLinkElement::shouldLoadLink() {
   return isInDocumentTree() || (isConnected() && m_relAttribute.isStyleSheet());
 }
 
 bool HTMLLinkElement::loadLink(const String& type,
                                const String& as,
                                const String& media,
+                               const String& referrerPolicy,
                                const KURL& url) {
   return m_linkLoader->loadLink(
       m_relAttribute,
       crossOriginAttributeValue(fastGetAttribute(HTMLNames::crossoriginAttr)),
-      type, as, media, url, document(), NetworkHintsInterfaceImpl());
+      type, as, media, referrerPolicy, url, document(),
+      NetworkHintsInterfaceImpl());
 }
 
 LinkResource* HTMLLinkElement::linkResourceToProcess() {
   if (!shouldLoadLink()) {
     DCHECK(!linkStyle() || !linkStyle()->hasSheet());
     return nullptr;
   }
 
   if (!m_link) {
     if (m_relAttribute.isImport()) {
@@ skipping 227 matching lines @@
   LinkLoaderClient::trace(visitor);
   DOMTokenListObserver::trace(visitor);
 }
 
 DEFINE_TRACE_WRAPPERS(HTMLLinkElement) {
   visitor->traceWrappers(m_relList);
   HTMLElement::traceWrappers(visitor);
 }
 
 }  // namespace blink