chromium/third_party/blink/web_tests/external/wpt/layout-instability/sticky-layout-no-change.html

<!DOCTYPE html>
<title>Layout Instability: sticky positioned layout no change</title>
<link rel="help" href="https://wicg.github.io/layout-instability/" />
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/util.js"></script>
<div style="height: 3000px"></div>
<div id="sticky" style="position: sticky; width: 200px; height: 300px; bottom: 0">
  <div style="will-change: transform; height: 3000px; background: yellow"></div>
</div>
<script>

promise_test(async () => {
  const watcher = new ScoreWatcher;

  // Wait for the initial render to complete.
  await waitForAnimationFrames(2);

  // This doesn't change layout because the sticky element sticks to the bottom.
  sticky.style.marginTop = "-1000px";

  await waitForAnimationFrames(3);
  assert_equals(watcher.score, 0);
}, 'Sticky layout no change.');

</script>