chromium/third_party/blink/web_tests/media/controls/repaint-on-resize.html

<!DOCTYPE html>
<title>Test that the controls repaint correctly on resize.</title>
<video controls width=200></video>
<script>
var video = document.querySelector("video");

if (window.testRunner)
  testRunner.waitUntilDone();

video.onloadedmetadata = function() {
  video.currentTime = 2;
  video.style.width = "300px";

  if (window.testRunner)
    testRunner.notifyDone();
};

video.src = "../content/test.ogv";
</script>