<!DOCTYPE html>

<html>
<head>
    <style>
        .container {
            position: relative;
            height: 200px;
            width: 500px;
            border: 1px solid black;
            overflow: hidden;
            z-index: 0;
        }
        
        .box {
            position: absolute;
            width: 200px;
            height: 200px;
            background-color: blue;
        }
        
        .composited {
            -webkit-transform: translateZ(1px);
        }
        
        pre {
            margin-top: 450px;
        }
    </style>
    <script>
        if (window.testRunner)
            testRunner.dumpAsText();

        function dumpLayers()
        {
            if (window.internals)
                document.getElementById('layers').innerText = internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_VISIBLE_RECTS)
        }
        window.addEventListener('load', dumpLayers, false);
    </script>
</head>
<body>

<div class="composited box" style="top: -120px; left: -100px"></div>
<div class="composited box" style="top: 200px; left: -100px"></div>

<pre id="layers">Layer tree goes here when testing</pre>
</body>
</html>