Fixing custom element type extensions to have correct native type

Source/bindings/dart/DartCustomElementBinding.h

Index: Source/bindings/dart/DartCustomElementBinding.h
diff --git a/Source/bindings/dart/DartCustomElementBinding.h b/Source/bindings/dart/DartCustomElementBinding.h
index 98e702f3c8d142c90d4b92866b942b5529ef58fe..3b5577325a510b64384da06f5612773057c0d692 100644
--- a/Source/bindings/dart/DartCustomElementBinding.h
+++ b/Source/bindings/dart/DartCustomElementBinding.h
@@ -40,13 +40,15 @@ 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;
 };
 
 }