Firefox does it too, and in a much more obvious way than either Chrome or Safari. Here are all the latest browsers on Mac compared: http://imgur.com/a/jdcI7 (Sorry Opera; I haven't re-installed you yet.)
I actually didn't get any permissions dialog or warning label in Safari 6; maybe I ok'd it for another site at some point in the past, but I definitely didn't whitelist this domain.
Your browser does not support the Fullscreen API.
The fact that this is a real technology being deployed right now doesn't hurt.