Add referrerpolicy support to link prefetch

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

Index: third_party/WebKit/Source/core/loader/LinkLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/LinkLoader.cpp b/third_party/WebKit/Source/core/loader/LinkLoader.cpp
index ddea909a2986908fde64e5c7f90b99963bf2183d..8c91554684908de98142f7e9cc8241a711d55311 100644
--- a/third_party/WebKit/Source/core/loader/LinkLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/LinkLoader.cpp
@@ -340,6 +340,29 @@ static Resource* preloadIfNeeded(const LinkRelAttribute& relAttribute,
   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,
@@ -399,13 +422,9 @@ bool LinkLoader::loadLink(const LinkRelAttribute& relAttribute,
                           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);
 
@@ -413,32 +432,16 @@ bool LinkLoader::loadLink(const LinkRelAttribute& relAttribute,
                      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)) {