With the upcoming Chrome release, whenever you sign into any Google website on Chrome, you will also be signed into Chrome with the same account, as reported earlier. You will also see your Google Account picture right in the Chrome UI, so you can easily see your sign-in status. When you sign out, either directly from Chrome or from any Google website, you’re completely signed out of your Google Account.
Google is clearly stating that this change to sign-in does not turn on Chrome sync. Users who want data like their browsing history, passwords, and bookmarks available on other devices must take additional action, such as turning on sync. The new change is to let users know which Google account is signed in. Google says that this is to prevent users from inadvertently performing searches or navigating to websites that could be saved to a different user’s synced account.
These changes will be available in the next release of Chrome; 70 which is slated to release in mid-October. It is also adding more control that allows users to turn off linking web-based sign-in with browser-based sign-in. For users that disable this feature, signing into a Google website will not sign them into Chrome. It is also updating its UIs to better communicate a user’s sync state.
In the current Chrome, the Google auth cookies allow you to stay signed in after cookies are cleared, but soon, Google will change this behavior that so all cookies are deleted and you will be signed out.