<!DOCTYPE html>
<html>
<head>
<script>
if (window.testRunner)
    testRunner.dumpAsText();

onload = function() {
    document.designMode = "on";
    document.execCommand("SelectAll");
    document.execCommand("RemoveFormat");
    document.body.textContent = "PASS if Blink doesn't crash.";
};
</script>
</head>
<body>
    <button><iframe></iframe></button>
</body>
</html>