unified styling on progress bars

turns out, with much interesting difficulty, you can actually
style html5 progress bars accross browsers. Do this so that the
colors are more consistent with what's already on the page. This
makes things a bit less visually jarring than chromes default
progress bars which completely dominate the page.

Change-Id: I5815114fbb3703e84c0cd696b5a3f285146c9025
Merge "unified styling on progress bars"