That's a feature of most "cloud" services that allow multi-device synchronisation.
It could be said Google already have your browsing history (of sites that they serve adverts on, or that use their analytics). I doubt Chrome's syncing data would give them any more information than what they have already.
Firefox provides synchronization without relying on 3rd-party servers, you can just use your own or one provided by a trusted friend.
and it's quite easy to block Google from tracking your browsing habits using GA or Ads: just use an Adblocker and something like Ghostery, RequestPolicy or Disconnect to block Google Analytics.
It could be said Google already have your browsing history (of sites that they serve adverts on, or that use their analytics). I doubt Chrome's syncing data would give them any more information than what they have already.