Revert of shiny/driver: repace style mask and event constants deprecated since OSX 10.12

Reason for revert: constants not available on older OS X releases

Original issue's description:
> shiny/driver: repace style mask and event constants deprecated since OSX 10.12
> 
> Fixes golang/go#17413.
> 
> Change-Id: I4cc8a980fc1d6a45ceef48b282baa7a94663ae10
> Reviewed-on: https://go-review.googlesource.com/31539
> Reviewed-by: David Crawshaw <crawshaw@golang.org>
> 

Change-Id: I35bd4301ebf63689d6b7bb49a29b9ef85657ba1e
Reviewed-on: https://go-review.googlesource.com/31613
Reviewed-by: David Crawshaw <crawshaw@golang.org>
1 file changed