Make scrollbar visible in ionic content when using native scroll

I am using overflow-scroll = "true" to make ionic use native scrolling :

 <ion-content overflow-scroll = "true">
   <ion-list>
     <ion-item ng-repeat="foo in bar">
       {{foo.label}}
     </ion-item>
   </ion-list>
 </ion-content>

This really works great (performances are really good). The only problem is that the (vertical) scrollbar disappeared.

As per the documentation, I tried adding scrollbar-y="true" to ion-content, but that didn't work.

I also tried adding this to my css :

::-webkit-scrollbar {
    -webkit-appearance: none;
}

::-webkit-scrollbar:vertical {
    width: 11px;
}

::-webkit-scrollbar:horizontal {
    height: 11px;
}

::-webkit-scrollbar-thumb {
    border-radius: 8px;
    border: 2px solid white;
    background-color: rgba(0, 0, 0, .5);
}

::-webkit-scrollbar-track {
    background-color: #fff;
    border-radius: 8px;
}

... but that didn't work either.

This article (look for "native scrolling") says that the problem can be solved using css, though.

Does anybody know how to do it ?