lcp-sw.https.html | Explore in Territory

<!DOCTYPE HTML>
<meta charset=utf-8>

<body>
  <script>
    new PerformanceObserver(entries => {
        window.parent.postMessage(entries.getEntries()[0].toJSON());
    }).observe({ entryTypes: ["largest-contentful-paint"] });

    const image = document.createElement("img");
    image.src = "/images/green.svg";
    image.id = "theImage";
    document.body.appendChild(image);
  </script>
</body>

chromium/third_party/blink/web_tests/external/wpt/largest-contentful-paint/resources/lcp-sw.https.html