iframe-with-listener.html | Explore in Territory

<html>
<body>
<div id="iframenode">
Hello from the iframe.
</div>
<script>
document.getElementById("iframenode").addEventListener("iframeListener", () => { });
</script>
</body>
</html>

chromium/third_party/blink/web_tests/inspector-protocol/dom/resources/iframe-with-listener.html