Summary:All UIManager operations that affect the view hierarchy are executed via the `addUIBlock:` method, which queues them up to be executed after layout has been completed on the shadow queue.
One of the most expensive view operations is view creation, but since this doesn't actually depend on layout, there's no reason to delay it until the shadow operations have finished.
This diff modifies the `createView` method to dispatch view creation directly to the main thread instead of adding it to the UIBlock queue. This seems to result a measurable improvement in TTI.
(Credit to astreet, for implementing the same idea on Android, and thanks to oli for telling me about it!)
Reviewed By: javache
Differential Revision: D3155709
fb-gh-sync-id: 3ad1da9a8fee687aa7e0e023d668192d94dba340
fbshipit-source-id: 3ad1da9a8fee687aa7e0e023d668192d94dba340
c55ca61396