OAuth Authentication on tvOS

I've seen a few people comment on how OAuth is impossible on the new Apple TV due to the lack of any form of web view. In building Fetch for the Apple TV we needed to interact with an OAuth provider (Put.io) in order to authenticate. Before I even knew that the Apple TV didn't support a web view, I never in a million years thought about displaying one to authenticate users. It would have been a truly horrendous experience for the user. Instead, I looked to authenticate from a secondary device — an iPhone for example. The YouTube app…