Simplify Custom Element constructors to be functions, not wrappers

Source/core/dom/CustomElementRegistry.h

Index: Source/core/dom/CustomElementRegistry.h
diff --git a/Source/core/dom/CustomElementRegistry.h b/Source/core/dom/CustomElementRegistry.h
index 9ae6c860919184d5bc957b06984403d039ef6b66..7a822f6082c0c7e09404bb526b4b6c23dca7f549 100644
--- a/Source/core/dom/CustomElementRegistry.h
+++ b/Source/core/dom/CustomElementRegistry.h
@@ -32,8 +32,8 @@
 #define CustomElementRegistry_h
 
 #include "bindings/v8/ScriptState.h"
+#include "bindings/v8/ScriptValue.h"
 #include "core/dom/ContextDestructionObserver.h"
-#include "core/dom/CustomElementConstructor.h"
 #include "core/dom/CustomElementUpgradeCandidateMap.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/QualifiedName.h"
@@ -78,7 +78,7 @@ public:
     explicit CustomElementRegistry(Document*);
     ~CustomElementRegistry();
 
-    PassRefPtr<CustomElementConstructor> registerElement(WebCore::ScriptState*, const AtomicString& name, const Dictionary& options, ExceptionCode&);
+    ScriptValue registerElement(WebCore::ScriptState*, const AtomicString& name, const Dictionary& options, ExceptionCode&);
 
     bool isUnresolved(Element*) const;
     PassRefPtr<CustomElementDefinition> findFor(Element*) const;