Allow RegionOp to be used for stenciling

Change-Id: I03473573bfe3da1a2d0fff40205094f7ba9e13af
Reviewed-on: https://skia-review.googlesource.com/29320
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed