<!DOCTYPE html>
<script>
window.onload = function()
{
if (!window.testRunner || !window.internals)
return;
testRunner.dumpAsText();
document.body.offsetTop;
internals.startTrackingRepaints(document);
document.getElementById('a').style.top = '400px';
document.getElementById('b').style.left = '400px';
document.body.offsetTop;
var layerTree = internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_REPAINT_RECTS);
window.internals.stopTrackingRepaints(document);
document.getElementById('result').textContent = layerTree.indexOf('repaint') == -1 ? 'SUCCESS' : 'FAIL';
};
</script>
<style>
.fixed {
position: fixed;
top: 200px;
left: 200px;
width: 100px;
-webkit-backface-visibility: hidden;
}
</style>
There should be no repaint when the divs are moved.
<div class="fixed" id="a">A</div>
<div class="fixed" id="b">B</div>
<pre id="result"></pre>