Update YUVA mipmap generation path to take a GrRecordingContext

Again, SkImage-derived objects will only have native access to an image context. Passing in a recording context captures when the mipmaps will be generated.

Change-Id: I025845ee4ea6bd97aa6001c1de316e394e7c5817
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/197768
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
3 files changed