chromium/third_party/blink/web_tests/fast/dom/Window/window-open-parent-no-parent.html

<script>
if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.waitUntilDone();
}
window.open("resources/destination.html", "_parent");
</script>
<p>If you can still see this text, then the test of window.open(URL, "_parent") has failed.</p>