Add Protected checks to GL and Mock onCanCopySurface methods

Bug: skia:14298
Change-Id: Id3c024ca730b0970dadf92566f9c5c504315e8fe
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/699579
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
2 files changed