Google Chrome users are now automatically signed into the browser if they re signed into any other Google service, such as Gmail. A cryptographer and professor at Johns Hopkins University noticed his Gmail profile pic strangely and suddenly appearing in his browser window. Previously, this log-in feature was opt-in only; now, it s automatic, and users don t receive a notification. Google Chrome team said that being signed in does not mean that the browser will actually harvest and ship data to Google.
Source: https://threatpost.com/googles-forced-sign-in-to-chrome-raises-privacy-red-flags/137651/