sousa-gecko/testing/web-platform/tests/css/css-animations/crashtests/cancel-update.html

<!DOCTYPE html>
<link rel="help" href="https://crbug.com/40447203">
<link rel="help" href="https://issues.chromium.org/issues/40447203">
<title>Check that cancelling one running animation and updating another doesn't
crash.</title>
<style>
  @keyframes anim {
    from { background-color: blue; }
    to { background-color: red; }
  }

  @keyframes anim2 {
    from { opacity: 0; }
    to { opacity: 1; }
  }
</style>
<div id="target"></div>
<script>
  window.onload = () => {
    target.style.animation = "anim 1s, anim2 1s";
    target.offsetTop;
    target.style.animation = "anim2 2s";
    target.offsetTop;
  };
</script>