The main two CLs calved off (and landed independently) from this CL are:
https://skia-review.googlesource.com/c/skia/+/156761 (Add SkImage_Gpu::MakePromiseYUVATexture)
-- adds internal place holder for YUVA promise images (only returns Y channel)
https://skia-review.googlesource.com/c/skia/+/156140 (Add SkImage_Base API to access planar data)
-- adds ability to grab planes for testing purposes (not externally visible)
Bug: skia:7903
Bug: skia:8424
Change-Id: Id0f2f84851dacc66c2c266a30cafa0b628b12eb4
Reviewed-on: https://skia-review.googlesource.com/151983
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
e8e2bb1384