<!DOCTYPE html>

<html>
<head>
    <style>
        body {
            height: 1000px;
        }

        .box {
            height: 200px;
            width: 2200px;
            background: repeating-linear-gradient(to right, white, blue 400px);
        }
        
        .composited {
            transform: translateZ(0);
        }
    </style>
    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }
        
        function getUIScript()
        {
            return `
            (function() {
                uiController.removeViewFromWindow(function() {
                    uiController.uiScriptComplete('');
                });
            })();`
        }

        function dumpTiles(outputId)
        {
            if (window.internals) {
                document.getElementById(outputId).innerText = internals.layerTreeAsText(document,
                    internals.LAYER_TREE_INCLUDES_VISIBLE_RECTS | internals.LAYER_TREE_INCLUDES_TILE_CACHES);
            }
        }
        function doTest()
        {
            if (!testRunner.runUIScript)
                return;

            dumpTiles('before-layers');

            testRunner.runUIScript(getUIScript(), function(result) {
                dumpTiles('after-layers');
                if (window.testRunner)
                    testRunner.notifyDone();
            });
        }
        window.addEventListener('load', doTest, false);
    </script>
</head>
<body>
    <div class="composited box">Tiled box</div>

<pre id="before-layers">Layer tree goes here</pre>
<pre id="after-layers">Layer tree goes here</pre>
</body>
</html>