nw.js

var { Cc, Ci } = require("chrome");

var L = console.log;
var pp = function(o) { return JSON.stringify(o,null,'  '); };

var wm = Cc["@mozilla.org/appshell/window-mediator;1"].getService(Ci.nsIWindowMediator);
var gWin = wm.getEnumerator("navigator:browser").getNext();

L(pp(Object.keys(gWin)));


var _getChromeWindow = function (aWindow) {
 	var chromeWin = aWindow.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIWebNavigation).QueryInterface(Ci.nsIDocShell).chromeEventHandler.ownerDocument.defaultView;
	return chromeWin;
};

var _getNativeWindow = function (gWin) {
	var nativeWindow = null;
	try {
		var chromeWin = _getChromeWindow(gWin).wrappedJSObject;
	 	if (chromeWin.NativeWindow) {
	    	nativeWindow = chromeWin.NativeWindow;
		} else {
		    L("NativeWindow not available on window");
		}
	} catch (e) {
	 	// If any errors happen, just assume no native window helper.
		L("No NativeWindow available: " + e);
	}
 return nativeWindow;
};