<!DOCTYPE html>
<meta charset="utf-8" />
<script>
    const url = new URL(new URLSearchParams(location.search.substr(1)).get('url'), location.href);
    const before = performance.now();
    fetch(url)
        .then(r => r.text())
        .then(() =>
            parent.postMessage({
                before,
                after: performance.now(),
                entry: performance.getEntriesByName(url)[0].toJSON()
            }));
</script>
