Yes, though you can encrypt it locally before it does so.

But do you do? (Honest question; I mean: is there a reliable and easy way to enforce encryption happens?)

Yes, it's a simple option in the settings: https://i.imgur.com/0np3ItM.png

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.

By default Google encrypts it. Its clearly in that picture

No, danielsamuels has manually changed that setting. The default is to only encrypt saved passwords: https://www.spinda.net/files/chromesync.png

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.

Thanks, and thanks for the precise screenshot :)