I had Chrome installed on my iPhone for the first time since I have ever performed a restore like this. ( I was getting jumbled cover art on albums and a restore seems to have solved it ) During this process, I was asked to setup the phone, first I think I had to unlock it, then wait some time, then set my location, then some security questions, and then a new screen I had not seen before, where there was Safari and Chrome listed, and I needed to pick one.
The problem is I was rushing, waiting for a phone call and didn't want to miss it. While in this setup mode the 3G radio icon was not on so I wanted to get back up and running. I didn't read what this screen does, chose Safari, and moved on.
I remember thinking to myself, hmpf, odd, Apple asking what default browser I want to use, that's a first. But it was what first came to mind. I can't say for sure that is what it was, as I didn't take the time to read the screen.
It's such a painless process, I may restore my phone again to answer this question. If I do, I will report it back here.