$ window.outerWidth is different in chrome & mozilla

Question

I'm new to angularjs and I stumbled upon this angular component of the $ window service. While trying to figure it out I have this snippet

<div ng-app="miniapp" ng-controller="AppController">
</div>

Js

var demoFunction =(function(){
var app = angular.module('miniapp', []);
app.controller("AppController",['$scope','$window',function($scope,$window){
            alert($window.outerWidth);   
   }]);
}())

jsfiddle

But surprisingly, I see different values ​​in Chrome and Mozilla, even if the window has the same aspect ratio.