<!DOCTYPE html>

<html>
<head>
  <style type="text/css" media="screen">
    iframe {
        border: 10px solid black;
        padding: 5px;
        margin: 50px;
        height: 170px;
        width: 320px;
        float: left;
    }
    
    #overlay {
        position: absolute;
        width: 150px;
        height: 50px;
        top: 5px;
        left: 5px;
        background-color: rgba(0, 0, 0, 0.6);
    }
    
    pre {
        clear: both;
    }
  </style>
  <script type="text/javascript" charset="utf-8">
    if (window.testRunner) {
        testRunner.dumpAsText();
        testRunner.waitUntilDone();
    }

    function doTest()
    {
        // Need to wait for compositing layers to be updated.
        window.setTimeout(function() {
          document.getElementById('overlay').style.height = '150px';
            if (window.testRunner) {
                testRunner.displayAndTrackRepaints(); // Painting has to happen to detect overlap.
                document.getElementById('layers').innerHTML = window.internals.layerTreeAsText(document);
                testRunner.notifyDone();
            }
        }, 0);
    }

    window.addEventListener('load', doTest, false);
  </script>
</head>
<body>

    <!-- Test that the parent document becomes composited when the iframe becomes overlapped. -->
    <!-- The iframe does not start with a RenderLayer. -->
    <iframe id="iframe" src="resources/composited-subframe.html"></iframe>

    <div id="overlay">
    </div>
    
    <pre id="layers">Layer tree appears here in DRT.</pre>
</body>
</html>