Password Alert will compare a hashed version of your password to a password you enter into a browser and a warning will be issued in the event that it finds you have entered a Google password to a non-Google website. Even though the warning will only be issued after a successful phishing, the user will still have enough time to change passwords or lock an account.
You can use this new Chrome extension called Password Alert here.
This facility can be extended to Google for Work accounts where alerts shall be issued to the respective administrator as well.
Because the code is open source, the new Google extension can easily adapt to other systems which can thereby help tighten security of other user accounts.