Summary:
Here we implement a bunch of helper methods that allow customizing the behavior of a RuntimeExecutor "on-demand" on the caller side. We will use it in the next diff(s).
Changelog: [Internal] Fabric-specific internal change.
Reviewed By: PeteTheHeat
Differential Revision: D20551411
fbshipit-source-id: 51d3cd02b69753110c0e1155347c6e52eb882c7d
Summary: Right now RuntimeExecutor is only used in Fabric. Moving it out of Fabric's uimanager/primitives.h and into react/utils so we can use it more broadly.
Reviewed By: shergin
Differential Revision: D16385366
fbshipit-source-id: 96063e536e1480bac078a9376fe55f7d8750477e