Reland "Some more clean-up of YUVA code"

This is a reland of c96740729a6a524ec4c768af84b876dcac1dbd7f

Original change's description:
> Some more clean-up of YUVA code
> 
> * Restore pre-colortype interface
> * Remove other colortype references
> 
> Bug: skia:7903
> Change-Id: I0db6d61e78d719ff941ac195bcbed4416f7d3138
> Reviewed-on: https://skia-review.googlesource.com/c/164610
> Commit-Queue: Jim Van Verth <jvanverth@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>

Bug: skia:7903
Change-Id: Iae89ccfa370433663bddf74c14cd1a0e5e6b6d4b
Reviewed-on: https://skia-review.googlesource.com/c/164688
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
6 files changed