Summary:
This is the first attempt to implement some base part of event dispatching pipeline from end-to-end.
Even when it is working, all this is still incomplete and generally up in the air. We are still messing proper implementation of event queue, priority, and synchronization of react reconciliation process with event scheduling.
Reviewed By: fkgozali
Differential Revision: D8212271
fbshipit-source-id: 92f9427d14726441c70ffff294ac95eeb004152a
Summary: This implements `EventHandlers` abstract class (aka "Events Guy") which encapsulates `eventDispatcher` and `instanceHandle` (and ownership of future `eventTarget`), all of this as part of existing {ShadowNode + Props + LayoutMetrics + LocalData + Descriptor + (and now) EventHandlers} infra. (We don't plan to add anything else to this model. Ever.)
Reviewed By: fkgozali
Differential Revision: D8053351
fbshipit-source-id: 1dd9ccbcbe5a2eb284b59ea351dc8beca645e8bf
Valentin Shergin