<!DOCTYPE html>
<html>
<head>
    <style>
        #box {
            height: 100px;
            width: 100px;
            margin: 10px;
            -webkit-backdrop-filter: blur(10px);
            -webkit-box-reflect: below 10px;
        }
        
        #box.changed {
            width: 110px;
        }
    </style>
    <script>
        if (window.testRunner) {
            testRunner.waitUntilDone();
            testRunner.dumpAsText();
        }
            
        function doTest()
        {
            setTimeout(() => {
                document.getElementById('box').classList.add('changed');

                if (window.testRunner)
                    testRunner.notifyDone();
            }, 0);
        }
        window.addEventListener('load', doTest, false);
    </script>
</head>
<body>
    <p>This test should not crash.</p>
    <div id="box">
        box
    </div>
</body>
</html>