This will be implemented in Metal and SPIR-V in followup CLs.
Change-Id: I397b4db40b15dd54cf1d8a17f414c3fe184b48d2
Bug: skia:10851
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/387638
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
