ng-hide is not getting updated dynamically

I have below div element with nghide

 <div ng-hide="showdiv" class="btnshowall"> 
    <a class="button button-block round outline"
       style="background: transparent !important;" >
      Show All
    </a>
 </div>

and controller as below

.controller('mapCtrl', ['$scope', '$stateParams','User','$cordovaGeolocation','geoFireFac','GoogleMapFac','ConnectivityMonitor','PhysioFac','User',
function ($scope, $stateParams,User,$cordovaGeolocation,geoFireFac,GoogleMapFac,ConnectivityMonitor,PhysioFac,User) {

    console.log('called mapctrl');  
    GoogleMapFac.setUserLoc($scope.map);
    $scope.showdiv = User.getShowDiv();


}])

and User service as

.service('User', ['ToastFac',function(ToastFac){
    return {
         showDiv : false,
        changeShowDiv : function(){
            console.log('in changeShowDiv before change '+this.showDiv);
            this.showDiv = !this.showDiv;
            console.log('in changeShowDiv after change '+this.showDiv);

        },

        getShowDiv : function(){
            return this.showDiv;
        }

I am invoking User.changeShowDiv() from google map's marker click event like below

google.maps.event.addListener(marker, 'click', function () {
      alert('store id '+marker.get('store_id'));
      if(User.showDiv){
          console.log('in if');
          User.changeShowDiv();
          console.log('User.showDiv '+User.showDiv);
      }
      else{
          console.log('in else');
          User.changeShowDiv();
          console.log('User.showDiv '+User.showDiv);
      }

});

logs are coming as expected

in else
services.js:123 in changeShowDiv before change false
services.js:125 in changeShowDiv after change true
services.js:218 User.showDiv true
services.js:211 in if
services.js:123 in changeShowDiv before change true
services.js:125 in changeShowDiv after change false
services.js:213 User.showDiv false
services.js:216 in else
services.js:123 in changeShowDiv before change false
services.js:125 in changeShowDiv after change true
services.js:218 User.showDiv true

By default, as User.showDiv variable is false, showAll button is visible. But button is not hiding & coming by marker click events.

Could someone guide me what I am missing.