nsComputedDOMStyle::GetPropertyValue(const nsAString& aPropertyName, nsAString& aReturn)
nsComputedDOMStyle::GetPropertyValue(const nsAReadableString& aPropertyName, nsAWritableString& aReturn)
nsComputedDOMStyle::GetPropertyValue(const nsAString& aPropertyName,                                     nsAString& aReturn){  nsCOMPtr<nsIDOMCSSValue> val;  aReturn.Truncate();  nsresult rv = GetPropertyCSSValue(aPropertyName, getter_AddRefs(val));  NS_ENSURE_SUCCESS(rv, rv);  if (val) {    rv = val->GetCssText(aReturn);  }  return rv;}