HTMLOptionsCollection remove() argument should be long, not unsigned long

Source/core/html/HTMLOptionsCollection.idl

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  * Copyright (C) 2013, 2014 Samsung Electronics. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 12 matching lines @@
 
 [
     DependentLifetime,
     SetWrapperReferenceFrom=ownerNode,
 ] interface HTMLOptionsCollection : HTMLCollection {
     // inherits item()
     [Custom=Setter, RaisesException=Setter] attribute unsigned long length; // shadows inherited length
     // FIXME: The spec has a legacycaller HTMLOptionElement? (DOMString name);
     [RaisesException, TypeChecking=Interface] setter void (unsigned long index, HTMLOptionElement? option);
     [RaisesException, TypeChecking=Interface] void add((HTMLOptionElement or HTMLOptGroupElement) element, optional (HTMLElement or long)? before = null);
-    // FIXME: the index argument should be long, not unsigned long.
-    void remove(unsigned long index);
+    void remove(long index);
     attribute long selectedIndex;
     // FIXME: Neither of these getters are in the spec, and the
     // getters inherited from HTMLCollection always return an Element.
     [ImplementedAs=item] getter Node (unsigned long index);
     [ImplementedAs=namedGetter] getter (NodeList or Element)? namedItem(DOMString name);
 };