chromium/src/third_party/blink/web_tests/compositing/overflow/composited-sticky-element.html

<script>
onload = function() {
  scroller.scrollTop = 100;
}
</script>
<style>
.composited {
  /* Triggers promotion without creating stacking context. */
  backface-visibility: hidden;
}

#scroller {
  height: 200px;
  overflow: auto;
  width: 200px;
}

.sticky {
  position: sticky;
  top: 0;
  height: 50px;
  background: green;
}
.spacer {
  height: 2000px;
}
</style>
<div id="scroller" class="composited">
  <div class="composited sticky"></div>
  <div class="spacer"></div>
</div>