Am I Running Liferay (TamperMonkey)

amirunningliferay_chrome.js

// ==UserScript==
// @name           Am I Running Liferay?
// @namespace      http://userscripts.org/users/23423423
// @include        *
// @connect        *
// @grant        unsafeWindow
// @grant        GM_xmlhttpRequest
// ==/UserScript==

var createBanner = function () {
	var body = document.body;

	var banner = document.body.innerHTML += '<div style="position: fixed; top: 0; width: 100%; background: #ffc; opacity: 0.9;border-bottom: 1px solid #FFCC00; padding: 10px; font-weight: bold; z-index: 1000000">This website is running Liferay! <a href="javascript: ;" id="amILiferayHide">Hide</a> - <a href="javascript: ;" id="amILiferayDiscard">Stop showing for this domain</a></div>';

	bindBanner();
};

function bindBanner() {
		var hideMessage = function(el) {
			unsafeWindow.console.log(el);
			el.parentNode.removeChild(el);
		};

		// var console = unsafeWindow.console;
		document.getElementById('amILiferayHide').addEventListener('click', function(event) {
			hideMessage(this.parentNode);
		}, false);

		document.getElementById('amILiferayDiscard').addEventListener('click', function() {

			var container = this.parentNode;
			container.innerHTML = 'This website will no longer notify you (at least until you clear your cookies!)';
			container.style.backgroundColor = '#F4FDEF';
			container.style.borderColor = '#ACDFA7';
			container.style.color = '#384F34';
			container.style.opacity = 1;

			var name = 'amiliferay_greasemonkey';
			var value = 'dontshow';
			var expires = (365 * 24 * 60 * 60 * 1000);

			var date = new Date();
			date.setTime(date.getTime() + expires);

			expires = '; expires=' + date.toGMTString();

			var path = '';
			var domain = '';
			var secure = '';

			document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join('');

			setTimeout(
				function() {
					hideMessage(container);
				}, 5000);
			}, false);
	}

var cookie = document.cookie;
var console = unsafeWindow.console;

if (cookie.indexOf('amiliferay_greasemonkey=dontshow') == -1) {
	// console.log(location.hostname, unsafeWindow.Liferay);
	if (unsafeWindow.Liferay) {
		createBanner();
	}
	else {
		GM_xmlhttpRequest({
		  method:"GET",
		  url: unsafeWindow.location.href,
		  onload:function(details) {
			console.log(details);
			var headers = details.responseHeaders;
			var isLiferay = (headers.toLowerCase().indexOf('liferay-portal:') > -1);
			// console.log(headers);
			if (isLiferay) {
				createBanner();
			}
		  }
		});
	}
}