Hidden scrollbar - Chrome

I was trying to retest the issue #618 using a clean install but i have some issues with the scrollbar and to update the antimatter theme #658

I guess it's the #644 is causing the issue with the scrollbar.

The computed CSS:
`body {
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
overflow: hidden;
}
# admin-main .content-wrapper {

```
position: relative;
overflow-y: hidden;
height: calc(100vh - 4.2rem);
```

}`

If i remove the overflow hidden the scrollbar appears again.
I'm using Ubuntu 16.04 and Chrome 53.0.

Thanks!