Remove users stored under "Web Browsing With Google Smarts"

Google (via Chrome) is somehow caching anyone that logged in with a Gmail account and associating it with my Chrome Browser. Pictures and logins are now displayed in Chrome by going to:

Settings->"Web Browsing with Google Smarts"

There is no obvious way to delete the data displayed here and disable this feature. Does anyone have any ideas?

I'm using MacOS with Chrome v 68.0.3440.106