chromium/third_party/blink/web_tests/animations/hit-testing/composited-with-hit-testing.html

<!DOCTYPE html>
<style>
#target {
  width: 50px;
  height: 50px;
  background-color: green;
}
</style>
<div id=target></div>
<script>
testRunner.waitUntilDone();
var anim;
requestAnimationFrame(function() {
  anim = target.animate([
    {transform: 'translateX(0px)'},
    {transform: 'translateX(1000px)'},
  ], 1000);
  requestAnimationFrame(function() {
    eventSender.mouseMoveTo(1, 1);
    eventSender.mouseMoveTo(1, 2);
    anim.pause();
    anim.currentTime = 500;
    testRunner.notifyDone();
  });
});
</script>