https://thenextweb.com/google/2018/09/24/change-chrome-69s-forced-login-behaviour/

According to security researcher S. Bálint, any time someone using Chrome 69 logs into a Google service or site, they are also logged into Chrome-as-a-browser with that user account. Essentially, Google is forcefully logging users into Chrome.

Chrome browser’s privacy policy notes that if you are is not signed in, all the information is locally stored on your system. However, all the data – including your browser history and password autofill information –is sent to Google servers once you’re signed in. That leads users to believe that Chrome 69’s forced login policy is sharing user data with Google.