chromium/third_party/blink/web_tests/fast/dom/HTMLDocument/activeElement.html

<html>
    <head>
        <script>
            function test()
            {
                if (window.testRunner)
                    testRunner.dumpAsText();
                log(document.activeElement);
                document.getElementById('one').focus();
                log(document.activeElement + " id: " + document.activeElement.id);
                document.getElementById('two').focus();
                log(document.activeElement + " id: " + document.activeElement.id);
                document.getElementById('two').blur();
                log(document.activeElement);
            }
            function log(msg)
            {
                document.getElementById("console").appendChild(document.createTextNode(msg + "\n"));
            }
        </script>
    </head>
    <body onload="test()">
        <input id="one"><input id="two">
        <br>
        <pre id="console"></pre>
    </body>
</html>