This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
http://dev.w3.org/csswg/cssom/#the-pseudoelement-interface [[ PseudoElement implements GetStyleUtils; ]] This is missing in the generated document but exists in the PseudoElement.idl file. It works for Element which uses a partial interface. (I'll hardcode the implements statement in the source file until this bug is fixed.)