There is a new experimental flag in the last Chromium Build for Mac that you might be interested in.
Once you've enabled the chrome://flags/#enable-password-manager-reauthentication
flag, user who's trying to reveal a plain text password in chrome://settings/passwords
will be prompted to reauthenticate
with the User Mac OS password.
When you are authenticated, you won't need to reauthenticate anymore for one minute.