Summary:
There are some situatuins where a litho view can move without a mount occuring in that view. One situation is a litho view in a recycler view. If a neighbouring view is deleted or changes its width/height this will shift the whole recycler view. Since each view in the recycler view is typically a separate comonent tree. The children of the recycler view are not aware of their siblings changes through mount. And these situations do not count as a scroll which was the previous method of detecting change.
This is a work around to listen to on draw which seems to be fired in all situations.
Reviewed By: lblasa
Differential Revision: D40430777
fbshipit-source-id: a9c8196f31a6bdfd4a2fed398cfcaed190972959
a447712865