Add <link rel=preload> onload support for scripts and styles

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

Index: third_party/WebKit/Source/core/loader/DocumentLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/DocumentLoader.cpp b/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
index 074398824ef02635387beee3cf6a43ae4b6ae920..e33f8df50644659a31e47b0fd171f471376305d0 100644
--- a/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
@@ -160,7 +160,7 @@ const KURL& DocumentLoader::url() const
     return m_request.url();
 }
 
-void DocumentLoader::startPreload(Resource::Type type, FetchRequest& request)
+ResourcePtr<Resource> DocumentLoader::startPreload(Resource::Type type, FetchRequest& request)
 {
     ResourcePtr<Resource> resource;
     switch (type) {
@@ -196,6 +196,7 @@ void DocumentLoader::startPreload(Resource::Type type, FetchRequest& request)
 
     if (resource)
         fetcher()->preloadStarted(resource.get());
+    return resource;
 }
 
 void DocumentLoader::didChangePerformanceTiming()