Summary: `sizeThatFits:` can be expensive, this optimizes our measuring function so that we do not call it if we know that we are going to use the exact height and width that were passed-in.
Reviewed By: rnystrom
Differential Revision: D4023715
fbshipit-source-id: dc02703b50bafd168ffab62ed98a7f6342100cc9
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: Add flexbox support to UIViews via a category
Reviewed By: dshahidehpour
Differential Revision: D4002873
fbshipit-source-id: f89de3acdf8fd89c7801918dcad34ba9011dd025
