Summary:
This adds a flowified JS module for the FrameRateLogger native module and plugs
it into `ScrollResponder` and `AppRegistry`.
If there is no `FrameRateLogger` native module, then the function calls will be no-ops.
One major limitation is that we can't track animated/programatic scrolls because we don't
have reliable end events. Would be generally useful to add those in a followup though.
Reviewed By: fkgozali
Differential Revision: D4765694
fbshipit-source-id: f3bec771df6ac918200c1afd1a7d8b6da540a4e2
Spencer Ahrens