Logging in with google popup method;popup ownership


I have an app which has google as a login option. I want to create a mobile app and i was wondering how the performance of the popop method is as compared to redirect flow as explained here https://github.com/meteor/meteor/wiki/OAuth-for-mobile-Meteor-clients

My app is made in meteor. When a user clicks the google login button,is the popup going to open its own webview window internally in the app or is it going to use the android set default browser?.