Add HTMLPreloadScanner support for <link rel=preload>

third_party/WebKit/Source/core/html/parser/PreloadRequest.cpp

Index: third_party/WebKit/Source/core/html/parser/PreloadRequest.cpp
diff --git a/third_party/WebKit/Source/core/html/parser/PreloadRequest.cpp b/third_party/WebKit/Source/core/html/parser/PreloadRequest.cpp
index 27c92b9953fa6e85c21d0dbef6c35f2de94b4c9c..5957a05a1305189566bc8096c6f6b08f13282d8f 100644
--- a/third_party/WebKit/Source/core/html/parser/PreloadRequest.cpp
+++ b/third_party/WebKit/Source/core/html/parser/PreloadRequest.cpp
@@ -6,6 +6,7 @@
 
 #include "core/dom/Document.h"
 #include "core/fetch/FetchInitiatorInfo.h"
+#include "core/fetch/ResourceFetcher.h"
 #include "platform/CrossOriginAttributeValue.h"
 
 namespace blink {
@@ -33,6 +34,7 @@ FetchRequest PreloadRequest::resourceRequest(Document* document)
     initiatorInfo.position = m_initiatorPosition;
     ResourceRequest resourceRequest(completeURL(document));
     resourceRequest.setHTTPReferrer(SecurityPolicy::generateReferrer(m_referrerPolicy, resourceRequest.url(), document->outgoingReferrer()));
+    ResourceFetcher::determineRequestContext(resourceRequest, m_resourceType, false);
     FetchRequest request(resourceRequest, initiatorInfo);
 
     if (m_resourceType == Resource::ImportResource) {
@@ -46,6 +48,8 @@ FetchRequest PreloadRequest::resourceRequest(Document* document)
     request.clientHintsPreferences().updateFrom(m_clientHintsPreferences);
     request.setIntegrityMetadata(m_integrityMetadata);
 
+    if (m_requestType == RequestTypeLinkRelPreload)
+        request.setAvoidBlockingOnLoad(true);

[Nate Chapin, 2016/01/12 03:28:17]

It's unfortunate to need to set this in a second place, but I don't see a good
way to avoid that.

[Yoav Weiss, 2016/01/12 06:37:56]

agree

     return request;
 }