Me neither on Ubuntu 12.04, Chromium 18.0.1025.151. (I'd assume it's supposed to work on Chromium as well as Chrome?) It installs without a hitch, but the comments pages are totally unmodified — no percentages or color like the screenshot.

Hm, strange, it looks okay to me on my VM - Ubuntu 12.04 LTS, Chrome v20.0.1132.47