<!DOCTYPE html>
<html>
<head>
<style>
#container {
width: 200px;
height: 200px;
overflow: hidden;
border: 1px solid black;
}
.scroll-content {
height: 600px;
}
.inner {
position: relative;
width: 150px;
height: 150px;
margin-top: -10px; /* force overlap with the composited element */
margin-left: 10px;
box-sizing: border-box;
border: 40px solid black;
}
.composited {
height: 150px;
width: 100px;
will-change: transform;
}
</style>
<script>
if (window.testRunner)
testRunner.waitUntilDone();
function doTest()
{
window.setTimeout(function() {
var container = document.getElementById('container');
window.console.log('scrolling')
container.scrollTop = 100;
if (window.testRunner)
testRunner.notifyDone();
}, 0);
}
window.addEventListener('load', doTest, false);
</script>
</head>
<body>
<div id="container">
<div class="scroll-content">
<div class="composited"></div>
<div class="inner"></div>
</div>
</div>
</body>
</html>