unload-bubbles.html | Explore in Territory

<!doctype html>
<html>
<head><title>Document</title></head>
<body>
<h1>Document</h1>
<script>
window.addEventListener("load", function() {
  window.addEventListener("visibilitychange", event => {
    opener.postMessage({
                        target: event.target.nodeName,
                        state: document.visibilityState,
                        bubbles: event.bubbles
                      }, "*");
  });
  opener.postMessage("close", "*");
});
</script>
</body>
</html>

chromium/third_party/blink/web_tests/external/wpt/page-visibility/resources/unload-bubbles.html