<!DOCTYPE html>
<html>
<head>
<style>
html { overflow: hidden; }
body { margin: 0px; }
div { height: 100px; width: 100px; }
.fixed { position: fixed; }
.green { background-color: green; }
.red { background-color: red; }
.composited { will-change: transform; }
</style>
<script type="text/javascript">
function moveFixedDiv()
{
document.getElementById('fixedDiv').style.top = '200px';
}
window.addEventListener('load', moveFixedDiv, false);
</script>
</head>
<body style="height:2000px;">
<!-- You should see 1 green rectangle in the output and no red. -->
<div style="top: 200px; left: 100px;" class="fixed red"></div>
<div class="composited"><div id="fixedDiv" style="top: 500px; left:100px;" class="fixed green"></div></div></div>
</body>
</html>