Add unit and layout test to <link rel=preconnect>

Source/core/html/HTMLLinkElement.cpp

Index: Source/core/html/HTMLLinkElement.cpp
diff --git a/Source/core/html/HTMLLinkElement.cpp b/Source/core/html/HTMLLinkElement.cpp
index f29b9b2408e5766aaf9a94c157bcff2c3d769557..ac43176593312fd587abda504a4685992fbdccd6 100644
--- a/Source/core/html/HTMLLinkElement.cpp
+++ b/Source/core/html/HTMLLinkElement.cpp
@@ -51,6 +51,7 @@
 #include "core/inspector/ConsoleMessage.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
+#include "core/loader/NetworkHintsInterface.h"
 #include "core/style/StyleInheritedData.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "wtf/StdLibExtras.h"
@@ -204,7 +205,7 @@ bool HTMLLinkElement::shouldLoadLink()
 
 bool HTMLLinkElement::loadLink(const String& type, const String& as, const KURL& url)
 {
-    return m_linkLoader.loadLink(m_relAttribute, fastGetAttribute(HTMLNames::crossoriginAttr), type, as, url, document());
+    return m_linkLoader.loadLink(m_relAttribute, fastGetAttribute(HTMLNames::crossoriginAttr), type, as, url, document(), NetworkHintsInterfaceImpl());
 }
 
 LinkResource* HTMLLinkElement::linkResourceToProcess()