Scroll bar selection area is too small

Description

With the UI refresh, the width of the side panel scroll bar seems to have shrunk in Chrome.

Steps to reproduce:
1. Load a CMS site in Chrome.
2. Add gadgets to left panel until there is enough content to create the scroll bar.
3. Try to click on the scroll bar to scroll.

Expected:
Scroll bar is easily selected.

Actual:
Scroll bar can only be selected in a 1px wide area.