<!DOCTYPE html>
<html>
<head>
    <title>Tests that contentsOpaque is re-evaluated after a background style change</title>
    <style>
        .composited {
            margin: 20px;
            height: 300px;
            width: 300px;
            margin: 10px;
            background-color: silver;
            transform: translateZ(0);
        }
        
        .composited.changed {
            background: none;
        }
    </style>
    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }

        window.addEventListener('load', () => {
            setTimeout(() => {
                document.querySelector('.composited').classList.add('changed');
                if (window.internals)
                    document.getElementById('layers').textContent = window.internals.layerTreeAsText(document);
                if (window.testRunner)
                    testRunner.notifyDone();
            }, 0);
        }, false);
    </script>
</head>
<body>
    <div class="composited">Text here</div>
<pre id="layers"></pre>
</body>
</html>