chromium/third_party/blink/web_tests/external/wpt/element-timing/same-origin-redirects.html

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8" />
<title>This test validates element timing information for same-origin redirect chain.</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/element-timing-helpers.js"></script>
</head>
<body>
<script>
async_test(t => {
    assert_implements(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented");
    // First redirect
    let destUrl = '/common/redirect.py?location='
    // Second redirect
    destUrl += '/common/redirect.py?location='
    // Image without TAO headers.
    destUrl += '/element-timing/resources/square20.png';
    let beforeRender;
    new PerformanceObserver(t.step_func_done(entries => {
        assert_equals(entries.getEntries().length, 1, 'There should be one entry');
        const entry = entries.getEntries()[0];
        checkElement(entry, location.origin + destUrl, 'et', 'id', beforeRender,
                document.getElementById('id'));
    })).observe({entryTypes: ['element']});
    const image = document.createElement('img');
    image.src = destUrl;
    image.setAttribute('elementtiming', 'et');
    image.setAttribute('id', 'id')
    document.body.appendChild(image);
    beforeRender = performance.now();
}, 'Same-origin image redirect without TAO should have its renderTime set.');
</script>
</body>
</html>