<html>
<head>
<style>
#outer {
position: absolute;
top: 0px;
left: -1000px;
height: 300px;
width: 300px;
z-index: 1;
overflow: auto;
background-color: green;
}
#inner {
will-change: transform;
background-color: blue;
}
#overlap {
width: 500px;
height: 500px;
background-color: yellow;
will-change: transform;
}
</style>
<script type="text/javascript">
if (window.testRunner) {
testRunner.waitUntilDone();
}
function doTest()
{
if (window.internals) {
internals.forceCompositingUpdate(document);
}
// Move green div so that it overlaps the yellow div, and hence
// needs its own backing.
document.getElementById("outer").style.left = "0px";
if (window.testRunner) {
testRunner.notifyDone();
}
}
window.addEventListener('load', doTest, false);
</script>
</head>
<body>
<div id="outer">
<div id="inner"></div>
</div>
<div id="overlap"></div>
</body>
</html>