chromium/third_party/blink/web_tests/compositing/overflow/composited-scroller-can-be-normal-flow.html

<!DOCTYPE HTML>
<style>
.scroller {
    width: 100px;
    height: 100px;
    overflow: auto;
    border: 1px solid black;
}
.scrolled {
    width: 40px;
    height: 40px;
    background: green;
}
.fixed {
    width: 100px;
    height: 30px;
    position: fixed;
    background: blue;
    backface-visibility: hidden;
}
</style>
<script>
    if (window.internals)
        internals.settings.setPreferCompositingToLCDTextEnabled(true);
</script>
<div class="fixed"></div>
<div class="scroller">
    <div class="scrolled"></div>
    <div class="scrolled"></div>
    <div class="scrolled"></div>
    <div class="scrolled"></div>
</div>