Summary: Wrote some tests to make sure the associated objects we use for layout live and die with the objects. This was worthwhile because it made me realize UIView+CSSLayout wasn't enabled to ARC. As a result, my tests were failing because they weren't explicitly deallocing nodes.
Reviewed By: rnystrom
Differential Revision: D4023324
fbshipit-source-id: 5356cf4f0522582d75f83b5eb2193d9bc8d63aee
Summary: If views are hidden on screen, we don't want to bother including them in layout calculations.
Reviewed By: rnystrom
Differential Revision: D4022992
fbshipit-source-id: 2e93eb911f26223f305ef7ce788f86d050b83e4a
Summary: I'm going to make some changes, but first, I want to get testing setup.
Reviewed By: rnystrom
Differential Revision: D4022585
fbshipit-source-id: a48516faad0bcb1a9cf5610ab21da5ee099c6f16
