return clone->QueryInterface(NS_GET_IID(nsICSSRule), (void **)&aClone);
return CallQueryInterface(clone, &aClone);
CSSStyleRuleImpl::Clone(nsICSSRule*& aClone) const{  CSSStyleRuleImpl* clone = new CSSStyleRuleImpl(*this);  if (clone) {    return clone->QueryInterface(NS_GET_IID(nsICSSRule), (void **)&aClone);  }  aClone = nsnull;  return NS_ERROR_OUT_OF_MEMORY;}