Window xul centering and favicon

Add-ons Development
#1

Hello, I’ve read about [xul migration][1] and create the chrome directory along with its sub folder besides the one that cfx init created. I have a xul window in chrome/content/myextension.xul that pops up when I click the toolbar but the window doesn’t centering and the favicon in xul window doesn’t showed up too. How can I resolve this?
my lib/main.js

var buttons = require('sdk/ui/button/action');

var button = buttons.ActionButton({
  id: "myextension",
  label: "myextension",
  icon: {
    "16": "./con16.png",
    "24": "./icon24.png",
    "32": "./icon32.png",
  },
  onClick: handleClick
});

function handleClick(state){
  var win = require('sdk/window/utils');
  win.open('chrome://myextension/content/myextension.xul', 'myextension', 'chrome,centerscreen');
//title and centering doesn't work
    }

my chrome/content/myextension.xul

<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet href="chrome://global/skin" type="text/css"?>
<!DOCTYPE window>
<window xmlns:html="http://www.w3.org/1999/xhtml" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" title="myextension" >
<!-- <html:link rel="icon" href="chrome://myextension/content/favicon.png" style="display:none"/> not showing -->
    <iframe type="content" src="chrome://myextension/content/myextension.html" width="700" height="400" /></window>

Regards,
Bakti
[1]: https://developer.mozilla.org/en-US/Add-ons/SDK/Guides/XUL_Migration_Guide

#2

Ah, it seems that firefox in upgraded version windows 10 has something to do with this. I’ve test it in linux mint and the window pops up corectly in the center without the need to adding any parameter. Will keep updating.

Thank you.