chromium/third_party/blink/web_tests/paint/invalidation/details-open-repaint.html

<!DOCTYPE html>

<script src="resources/text-based-repaint.js"></script>
<script>
window.onload = runRepaintAndPixelTest;

function repaintTest() {
  document.getElementsByTagName('details')[0].setAttribute('open', true);
}
</script>

<p>This test passes if the arrow rotates to the open position.</p>
<details>
  <input>
  <summary>summary</summary>
</details>