I don't think this is for tracking. If this was just for tracking, there are much simpler and discreet ways to do it (just add a background ping). I think this

I don't think this is for tracking. If this was just for tracking, there are much simpler and discreet ways to do it (just add a background ping). I think this is to allow intercepting the user if Google determines that the link destination is harmful (eg malware distribution).