I'm missing the scroll bar too, it's really annoying. After looking at the stylesheet it looks like it's due to this rule: body::-webkit-scrollbar { width: 0!important; }. If you remove that rule the scroll bar will be visible again. Here's some JavaScript that you can copy-paste into the address bar to fix it (only tested on Chromium):

    javascript:void(_(document.styleSheets).chain().pluck('rules').map(_.flatten).flatten(true).findWhere({selectorText:"body::-webkit-scrollbar"}).value().style.removeProperty('width'))