<script>
    function runTest() {
        var observer = new MutationObserver(()=>{p1.replaceWith(p2)});
        observer.observe(select,{childList:true});
        select[2] = option;
        document.head.appendChild(p2);
        var object = document.createElement("object");
        var frame = document.createElement("frame");
        audio.appendChild(option);
        p1.appendChild(object);
        object.data = "abc";
        document.all[9].appendChild(frame);
		if (window.testRunner) {
			testRunner.dumpAsText();
			alert("test passed because nothing crashed");
		}
    }
</script>
<body onload=runTest()>
    <p id="p1">
        <p id="p2">
            <audio id="audio">
                <select id="select">
                    <option id="option"></option>
                </select>
            </audio>
        </p>
    </p>
</body>