Consolidate the scissor enums into one "GrScissorTest" enum

Bug: skia:
Change-Id: If8d40b54860acb5c18d3a9a82cb2a61e3c42025f
Reviewed-on: https://skia-review.googlesource.com/147172
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
10 files changed