NS_WARNING("nsJSRuntimeService is missing");
NS_ASSERTION(NS_SUCCEEDED(rv), "nsJSRuntimeService is missing");
extern "C" JSRuntime* PREF_GetJSRuntime(){  nsresult rv;  NS_WITH_SERVICE(nsIJSRuntimeService, rtsvc, "@mozilla.org/js/xpc/RuntimeService;1", &rv);  if (NS_SUCCEEDED(rv)) {    JSRuntime* rt;    rv = rtsvc->GetRuntime(&rt);    if (NS_SUCCEEDED(rv)) {      return rt;    }  }  NS_WARNING("nsJSRuntimeService is missing");  return nsnull;}