[graphite] Add YUVABackendTextures.

This is essentially a copy from and update to GrYUVABackendTextures.

Bug: b/238756380
Change-Id: Ia8d9c5740f4103a87bce32b5f025275e4ee36ae1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/651016
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
6 files changed