Add the revision details widget to sheriff-o-matic

Reproduce the functionality of the old revision details information
from garden-o-matic in sheriff-o-matic.

R=ojan@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/410483002

git-svn-id: svn://svn.chromium.org/blink/trunk@179666 bbb929c8-8fbe-4397-9dbb-9b2b20218538