<!doctype html>
<meta charset="utf-8">
<title>activeElement when focusing same-site iframe's contentWindow</title>
<script>
let log = "";
function getLog() {
    return log;
}
window.onmessage = function(e) {
    log += e.data;
};
window.onload = function() {
    log += "outeronload,";
    log += "activeElement:" + document.activeElement.tagName + ",";
    log += "willfocusiframe,";
    document.getElementsByTagName("iframe")[0].contentWindow.focus();
    log += "didfocusiframe,";
    log += "activeElement:" + document.activeElement.tagName + ",";
    log += "willbluriframe,";
    document.getElementsByTagName("iframe")[0].contentWindow.blur();
    log += "didbluriframe,";
    log += "activeElement:" + document.activeElement.tagName + ",";
    log += "willspineventloop,"
    opener.step_timeout(function() {
        opener.postMessage(getLog(), "*");
    }, 1500);
}
</script>
<iframe src="activeelement-after-focusing-same-site-iframe-inner-contentwindow.html"></iframe>