Make TransitionController a pure Swift class.

Authored by featherless on Mon, Apr 17, 3:33 PM.

Description

Make TransitionController a pure Swift class.

Summary: This improves autocompletion in Swift code at the cost of some Objective-C interop. We can still provide Objective-C interop in the future but we may do so using a separate API.

Reviewers: O2 Material Motion, O4 Material Apple platform reviewers, Material Motion, markwei

Reviewed By: O2 Material Motion, O4 Material Apple platform reviewers, Material Motion, markwei

Tags: Material Motion

Differential Revision: http://codereview.cc/D3059