I use tor browser for Gmail and Google+ account since April. It used to works good, but I have to switch on JavaScripts, of course. Gmail chat used to works good, but since today or yesterday Google changed chats to hangouts. I have to log to Google one time more for chats, but if I log in, chats still are not aviable (exit IP is the same like exit node to Gmail, and activity on Gmail shows log in from firefox and sometimes from mobile). I have heard too - that Google talk (not only with Tor but normal too) do not work anymore. I have tried it with "Allow scripts globally" but it was with the same result.
I use Tor browser for windows, which was downloaded from torproject.org (with latest actualization).
I have find similar question, but in this time Google chat works good. It stop work today or yesterday. I cannot log-in, in hangout when using Tor Browser