Make CSSSupportsRule function arguments non-optional

Source/core/css/CSSSupportsRule.idl

 /* Copyright (C) 2012 Motorola Mobility 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:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above
  *    copyright notice, this list of conditions and the following disclaimer in
@@ skipping 14 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 [
     NoInterfaceObject
 ] interface CSSSupportsRule : CSSRule {
     readonly attribute CSSRuleList cssRules;
     readonly attribute DOMString conditionText;
 
-    [RaisesException] unsigned long insertRule([Default=Undefined] optional DOMString rule,
-                             [Default=Undefined] optional unsigned long index);
-    [RaisesException] void deleteRule([Default=Undefined] optional unsigned long index);
+    [RaisesException] unsigned long insertRule(DOMString rule, unsigned long index);
+    [RaisesException] void deleteRule(unsigned long index);
 };