<!DOCTYPE html>
<style>
#container {
    position: fixed;
    top: 200px;
    left: 100px;
}

#block {
    position: relative;
    width: 100px;
    height: 100px;
    top: 50px;
    background-color: green;
}

#composited-non-stacking-context {
    width: 20px;
    height: 20px;
    background-color: white;
    backface-visibility: hidden;
}
</style>
<div id="container">
    <div id="composited-non-stacking-context">
        <div id="block"></div>
    </div>
</div>
This test passes if the green block stays at the same place after repaint.
<script src="../../resources/run-after-layout-and-paint.js"></script>
<script>
runAfterLayoutAndPaint(function() {
    document.getElementById("container").style.top = "100px";
    document.getElementById("block").style.top = "100px";
}, true);
</script>