Add referrerpolicy support to link prefetch

third_party/WebKit/Source/core/loader/LinkLoader.cpp

 /*
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 322 matching lines @@
   if (settings && settings->logPreload()) {
     document.addConsoleMessage(ConsoleMessage::create(
         OtherMessageSource, DebugMessageLevel,
         String("Preload triggered for " + href.host() + href.path())));
   }
   linkRequest.setForPreload(true, monotonicallyIncreasingTime());
   linkRequest.setLinkPreload(true);
   return document.loader()->startPreload(resourceType, linkRequest);
 }
 
+void LinkLoader::prefetchIfNeeded(Document& document,
+                                  const KURL& href,
+                                  const LinkRelAttribute& relAttribute,
+                                  CrossOriginAttributeValue crossOrigin,
+                                  ReferrerPolicy referrerPolicy) {
+  if (relAttribute.isLinkPrefetch() && href.isValid() && document.frame()) {
+    UseCounter::count(document, UseCounter::LinkRelPrefetch);
+
+    ResourceRequest resourceRequest(document.completeURL(href));

[Mike West, 2016/11/07 09:52:43]

You could avoid creating this intermediate object by constructing
`linkRequest(document.completeURL(href), ...)` and then manipulating
`linkRequest.mutableResourceRequest()`. *shrug* Up to you, but that seems
simpler to me.

[Yoav Weiss, 2016/11/08 09:23:53]

Yeah, slightly simpler I guess. Changed

+    if (referrerPolicy != ReferrerPolicyDefault) {
+      resourceRequest.setHTTPReferrer(SecurityPolicy::generateReferrer(
+          referrerPolicy, href, document.outgoingReferrer()));
+    }
+    FetchRequest linkRequest(resourceRequest, FetchInitiatorTypeNames::link);
+    if (crossOrigin != CrossOriginAttributeNotSet) {
+      linkRequest.setCrossOriginAccessControl(document.getSecurityOrigin(),
+                                              crossOrigin);
+    }
+    setResource(LinkFetchResource::fetch(Resource::LinkPrefetch, linkRequest,
+                                         document.fetcher()));
+  }
+}
+
 void LinkLoader::loadLinksFromHeader(
     const String& headerValue,
     const KURL& baseURL,
     Document* document,
     const NetworkHintsInterface& networkHintsInterface,
     CanLoadResources canLoadResources,
     MediaPreloadPolicy mediaPolicy,
     ViewportDescriptionWrapper* viewportDescriptionWrapper) {
   if (!document || headerValue.isEmpty())
     return;
@@ skipping 39 matching lines @@
 
 bool LinkLoader::loadLink(const LinkRelAttribute& relAttribute,
                           CrossOriginAttributeValue crossOrigin,
                           const String& type,
                           const String& as,
                           const String& media,
                           ReferrerPolicy referrerPolicy,
                           const KURL& href,
                           Document& document,
                           const NetworkHintsInterface& networkHintsInterface) {
-  // TODO(yoav): Do all links need to load only after they're in document???
+  if (!m_client->shouldLoadLink())
+    return false;
 
-  // TODO(yoav): Convert all uses of the CrossOriginAttribute to
-  // CrossOriginAttributeValue. crbug.com/486689
-
-  // FIXME(crbug.com/463266): We're ignoring type here, for everything but
-  // preload. Maybe we shouldn't.
   dnsPrefetchIfNeeded(relAttribute, href, document, networkHintsInterface,
                       LinkCalledFromMarkup);
 
   preconnectIfNeeded(relAttribute, href, document, crossOrigin,
                      networkHintsInterface, LinkCalledFromMarkup);
 
   bool errorOccurred = false;
-  if (m_client->shouldLoadLink()) {
-    createLinkPreloadResourceClient(preloadIfNeeded(
-        relAttribute, href, document, as, type, media, crossOrigin,
-        LinkCalledFromMarkup, errorOccurred, nullptr, referrerPolicy));
-  }
+  createLinkPreloadResourceClient(preloadIfNeeded(
+      relAttribute, href, document, as, type, media, crossOrigin,
+      LinkCalledFromMarkup, errorOccurred, nullptr, referrerPolicy));
   if (errorOccurred)
     m_linkLoadingErrorTimer.startOneShot(0, BLINK_FROM_HERE);
 
   if (href.isEmpty() || !href.isValid())
     released();
 
-  // FIXME(crbug.com/323096): Should take care of import.
-  if (relAttribute.isLinkPrefetch() && href.isValid() && document.frame()) {
-    if (!m_client->shouldLoadLink())
-      return false;
-    UseCounter::count(document, UseCounter::LinkRelPrefetch);
-
-    FetchRequest linkRequest(ResourceRequest(document.completeURL(href)),
-                             FetchInitiatorTypeNames::link);
-    if (crossOrigin != CrossOriginAttributeNotSet) {
-      linkRequest.setCrossOriginAccessControl(document.getSecurityOrigin(),
-                                              crossOrigin);
-    }
-    setResource(LinkFetchResource::fetch(Resource::LinkPrefetch, linkRequest,
-                                         document.fetcher()));
-  }
+  prefetchIfNeeded(document, href, relAttribute, crossOrigin, referrerPolicy);
 
   if (const unsigned prerenderRelTypes =
           prerenderRelTypesFromRelAttribute(relAttribute, document)) {
     if (!m_prerender) {
       m_prerender =
           PrerenderHandle::create(document, this, href, prerenderRelTypes);
     } else if (m_prerender->url() != href) {
       m_prerender->cancel();
       m_prerender =
           PrerenderHandle::create(document, this, href, prerenderRelTypes);
@@ skipping 19 matching lines @@
 
 DEFINE_TRACE(LinkLoader) {
   visitor->trace(m_client);
   visitor->trace(m_prerender);
   visitor->trace(m_linkPreloadResourceClient);
   ResourceOwner<Resource, ResourceClient>::trace(visitor);
   PrerenderClient::trace(visitor);
 }
 
 }  // namespace blink