<!DOCTYPE html>
<div>Test passes if it does not crash</div>
<script src="../../../resources/gc.js"></script>
<script>
if (window.testRunner) {
    testRunner.waitUntilDone();
    testRunner.dumpAsText();
}
var observer = new MutationObserver(function() {console.log('Should not appear')});
var div = document.createElement('div');
observer.observe(div, {attributes: true});
div.id = 'foo';
div = null;
observer = null;
gc();
setTimeout(function() { testRunner.notifyDone(); }, 0);
</script>