Fixing custom element type extensions to have correct native type

Source/bindings/dart/DartCustomElementBinding.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 22 matching lines @@
 
 #include "wtf/PassOwnPtr.h"
 #include "wtf/PassRefPtr.h"
 
 #include <dart_api.h>
 
 namespace WebCore {
 
 class DartCustomElementBinding {
 public:
-    static PassOwnPtr<DartCustomElementBinding> create(Dart_Handle customType);
+    static PassOwnPtr<DartCustomElementBinding> create(Dart_Handle customType, intptr_t nativeClassId);
 
     Dart_PersistentHandle customType() { return m_customType; }
+    intptr_t nativeClassId() { return m_nativeClassId; }
 
 private:
-    DartCustomElementBinding(Dart_Handle customType);
+    DartCustomElementBinding(Dart_Handle customType, intptr_t nativeClassId);
     Dart_PersistentHandle m_customType;
+    intptr_t m_nativeClassId;
 };
 
 }
 
 #endif // CustomElementBinding_h