<script>
if (window.testRunner)
testRunner.dumpAsText();
// This shouldn't leak document objects.
var e = new CustomEvent('custom', {'detail': new Error()});
</script>
<script>
if (window.testRunner)
testRunner.dumpAsText();
// This shouldn't leak document objects.
var e = new CustomEvent('custom', {'detail': new Error()});
</script>