The way to use Facebook native login on iOS 9, instead of Safari View Controller
From Facebook SDK version 4.6, Facebook uses Safari View Controller to login on iOS 9 instead of Facebook native app like before. They explain why here: https://developers.facebook.com/blog/post/2015/10/29/Facebook-Login-iOS9/
But i (maybe you too) don't think it is a good idea. Some one even show the proof how it affects to his app (http://stackoverflow.com/a/33155960)
So i write this. Hope Facebook update their SDK soon and let developer can decine the login behavior for their own app.
Just import those file into your project and you're ready to go. Enjoy it!