Show example of Federated login for Flutter web (add new code in library if needed)

[dhoffer]

You have a good example, example 19 of federated login but only for mobile devices. I need same but for Flutter Web. It seems it should be possible perhaps with already existing Flutter code as since on the web we should already have access to web views. Could you add an example of how to do this? If additional code is needed in your library please add that as well.

I only need support at the moment for Google but all federated partners for AWS Cognito should be supported.

Thanks,
-David