Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/35768
Changelog: [Internal]
This implements native side mechanics for reporting user events timing to JS (PerformanceObserver API).
See the standard for more details: https://www.w3.org/TR/event-timing/
The events are only logged when there are any active subscriptions (via `PerformanceObserver.observe`), also we only log "discrete events" (i.e. no likes of mouse move), so the overhead is non-existing.
There are two main metrics of interest for an event lifecycle:
* Time the event is spent in the queue, i.e. the time between it's created and dispatched
* Time that is spend in the event handler on the JS side (event dispatch), or processing time
Both of these are measured, and the corresponding fields are populated.
Reviewed By: sammy-SC
Differential Revision: D42294947
fbshipit-source-id: 4fd7938c04b942400befa4057d4929fb2763cee1
Ruslan Shestopalyuk
09ad0cc0c6