<!DOCTYPE html> <!-- webkit-test-runner [ AsyncOverflowScrollingEnabled=true ] -->
<html>
<style>
.testdiv {
    display: inline-block;
    box-sizing: border-box;
    border: 2px solid blue;
    position: relative;
    height: 200px;
    width: 200px;
    will-change: transform;
}
.inner {
    height: 200px;
    width: 200px;
    background-color: green;
}
.scroller {
    overflow: scroll;
    height: 50px;
    width: 50px;
}
.scrollcontent {
    height: 100px;
    background-color:red;
}
</style>
<script>
window.onload = function () {
    if (!window.internals)
        return;
    if (window.testRunner)
        testRunner.dumpAsText();

    results.innerText = "Before adding scroller:\n\n"
    results.innerText += internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_EVENT_REGION);

    scroller.removeAttribute("hidden");

    results.innerText += "After adding scroller:\n\n"
    results.innerText += internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_EVENT_REGION);
}
</script>
<body>
<div class="testdiv">
</div>
<div id="scroller" class="scroller" hidden><div class="scrollcontent"></div></div>

<pre id="results"></pre>
</body>
</html>