<!DOCTYPE html>

<html>
<head>
    <style>
        .box {
            height: 400px;
            width: 400px;
            top: 0;
            left: 0;
        }
        
        .child {
            position: absolute;
            height: 400px;
            width: 400px;
            background-color: red;
        }
        
        .composited {
            -webkit-transform: translateZ(0);
        }
        
        .fixed {
            position: fixed;
            top: -1000px;
        }
    </style>
    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }

        window.addEventListener('load', function() {
            window.setTimeout(function() {
                var box = document.getElementById('child');
                box.classList.remove('fixed');

                var box = document.getElementById('box');
                box.classList.add('composited');
                if (window.testRunner)
                    testRunner.notifyDone();
            }, 0);
        }, false);
    </script>
</head>
<body>
    <p>This test should not assert</p>
    <div id="box" class="box">
        <div id="child" class="fixed child">
        </div>
    </div>
</body>
</html>