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chromium
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chromium/third_party/blink/web_tests/http/tests/html/resources/validation-bubble-oopif-frame-2.html 

<!DOCTYPE html>
<body>
<p style="height:90px;">Origin: https://127.0.0.1:8443/</p>
<input type="email" value="foo">
<script>
document.querySelector('input').reportValidity();
</script>
</body>