<!DOCTYPE html>

<html>
<head>
    <style>
        body {
            width: 1100px;
            height: 1000px;
        }
        .fixed {
            position: fixed;
            top: 120px;
            left: 60px;
            width: 200px;
            height: 150px;
            background-color: rgba(0, 0, 0, 0.5);
            padding: 20px;
            box-sizing: border-box;
            color: white;
            box-shadow: 0 0 10px black;
        }
        
        #container {
            position: relative;
        }
        
        .dot {
            position: absolute;
            width: 10px;
            height: 10px;
            background-color: orange;
        }
    </style>
    <script>
        if (window.testRunner)
            testRunner.dumpAsText();

        if (window.internals)
            internals.settings.setAcceleratedCompositingForFixedPositionEnabled(true);

        function doTest()
        {
            setupDots();
            dumpLayers();
        }

        function setupDots()
        {
            var across = 40;
            var down = 50;
            var spacing = 20;
            var container = document.getElementById('container');
            
            for (var col = 0; col < across; ++col) {
                for (var row = 0; row < down; ++row) {
                    var div = document.createElement('div');
                    div.className = 'dot';
                    div.style.left = (col * spacing) + 'px';
                    div.style.top = (row * spacing) + 'px';
                    
                    container.appendChild(div);
                }
            }
        }

        function dumpLayers()
        {
            if (window.testRunner) {
                document.getElementById('layers').innerText = window.internals.layerTreeAsText(document);
            }
        }
        
        window.addEventListener('load', doTest, false);
    </script>
</head>
<body>
    <div class="fixed">
        Fixed layer.
    </div>
    <div id="container"></div>
<pre id="layers"></pre>
</body>
</html>