chromium/third_party/blink/web_tests/compositing/overflow/overflow-scrollbar-layers.html

<!DOCTYPE html>
<style>
.container {
width: 100px;
height:100px;
position:absolute;
will-change:transform;
overflow:auto;
}

.content {
will-change:transform;
position:absolute;
width:10px;
height:10px;
}

.tall {
height:200px;
}

.wide {
width:200px;
}

.resizeWidget {
resize: both;
}

</style>
<pre id="layerTree"></pre>
<div class="container">
  <div class="content tall"></div>
</div>
<div class="container">
  <div class="content wide"></div>
</div>
<div class="container">
  <div class="content wide tall"></div>
</div>
<div class="container resizeWidget">
  <div class="content"></div>
</div>
<script>
if (window.testRunner) {
    testRunner.dumpAsText();
    document.getElementById("layerTree").innerText = internals.layerTreeAsText(document);
}
</script>