It's not on by default though, meaning most users will be passing data their browsing data through Google unencrypted. Not only tabs but cookies, full browser history...
I'm always surprised that no one seems to think this a big deal. People will install and recommend tracking-blocking extensions while allowing Google to hoover up all this data without a second thought.
Oh okay, didn't know Chrome provided this feature natively, I thought you were referring to some kind of crazy DIY encrypt-things-behind-Chrome's-back monitoring script setup.