<style>
.container {
  width: 100px;;
  height: 100px;
  background-color: green;
  contain: paint;
}

.out-of-flow-child {
  position: absolute;
  top: -100px;
  background-color: red;
  width: 50px;
  height: 50px;
}
.overflow {
  width: 300px;
  height: 10px;
}
</style>
<!-- PASS if no red box. -->
<div id=scrollThis class=container>
  <div class=out-of-flow-child></div><div class=overflow></div>
</div>
<script>
scrollThis.scrollIntoView();
</script>