$watch on window.location not working

Currently creating a chrome extension which sits inside other applications. Currently, the application is an ember based app and therefore has it's url changes via javascript.

At some point this was working but I cannot get it to work any longer. Why doesn't it work?

        $rootScope.$watch(function(){
            return window.location;
        }, function(value){
            console.log(value)
            $rootScope.locationChanged();
        }, true)