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Test Info: Warnings
- This test has a WPT meta file that expects 1 subtest issues.
- This WPT test may be referenced by the following Test IDs:
- /paint-timing/with-first-paint/first-image-child.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<head>
<title>Performance Paint Timing Test: child ignores parent FCP</title>
<meta name="timeout" content="long">
</head>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<iframe src='../resources/subframe-sending-paint.html' id='child-iframe'></iframe>
<img src='../resources/circles.png'/>
<script>
setup({"hide_test_state": true});
async_test(function (t) {
assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");
window.addEventListener('message', t.step_func(e => {
// Child iframe should not have any paint-timing entries.
assert_equals(e.data, '0');
t.done();
}));
// Wait for onload to ensure img and iframe have loaded.
window.addEventListener('load', function() {
function testPaintEntries() {
const bufferedEntries = performance.getEntriesByType('paint');
if (bufferedEntries.length < 2) {
t.step_timeout(testPaintEntries, 20);
return;
}
t.step(function() {
assert_equals(bufferedEntries.length, 2, 'There should be two paint timing instances.');
assert_equals(bufferedEntries[0].entryType, 'paint');
assert_equals(bufferedEntries[0].name, 'first-paint');
assert_equals(bufferedEntries[1].entryType, 'paint');
assert_equals(bufferedEntries[1].name, 'first-contentful-paint');
// Ask child iframe to send its paint-timing entries.
document.getElementById('child-iframe').
contentWindow.postMessage('', '*');
})
}
testPaintEntries();
});
}, 'Child iframe ignores paint-timing events fired from parent image rendering.');
</script>
</body>
</html>