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

Source/core/html/HTMLOptionsCollection.idl

Index: Source/core/html/HTMLOptionsCollection.idl
diff --git a/Source/core/html/HTMLOptionsCollection.idl b/Source/core/html/HTMLOptionsCollection.idl
index f5840306c3361f676c537436ab741caa766b2db0..7a9fabfd63e862a952043cbff9b4d090f8c8741f 100644
--- a/Source/core/html/HTMLOptionsCollection.idl
+++ b/Source/core/html/HTMLOptionsCollection.idl
@@ -30,8 +30,7 @@
     // 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.