chromium/third_party/blink/web_tests/fast/block/positioned-movement-assert.html

<!doctype html>
<style>
#container {
    display: inline;
}

.target {
    position: relative;
    float: left;
    top: 10px;
    left: 10px;
}

.target:after {
    position: absolute;
    content: 'foo';
}
</style>
<p>crbug.com/454824: Don't mark ancestors for layout during positioned movement layout. This test should not assert. </p>
<div id="container">
    <div id="target1" class="target"></div>
</div>
<script>
    if (window.testRunner)
        testRunner.dumpAsText();
    document.body.offsetTop;
    var div = document.querySelector('#target1');
    div.style.left = '100px';
    div.style.top = '100px';
</script>