add flag to stage API change

Bug: skia:8937
Change-Id: I7882870677711409505cadfa8b7abe1130db8c72
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/206683
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Auto-Submit: Mike Reed <reed@google.com>
1 file changed