Summary:
There was a bug in the view clipping logic.
Clipping works on uiview hierarchy, but I've been using `reactSuperview` to get clipping rect for my parent.
This is incorrect in a case where these two hierarchies don't match and there are some views between a view and its `reactSuperview`.
So we should really use normal `superview`. A minor complication is that `superview` is `nil` if we are clipped.
We could remember what our last `superview` was, but that's extra data we have to manage. Instead I use one clever trick to avoid doing so.
(Let me know if it makes sense based on my inline documentation.)
Reviewed By: mmmulani
Differential Revision: D4182647
fbshipit-source-id: 779cbcec0bd08eb270c3727c9c5cb9c080c4a2a4
26e373c903