Reland "Release YUVA planes in SkImage_GpuYUVA after flattenning to RGBA."

This reverts commit bc0c460349142140295593a3a32d507f7b45c622.

Reason for revert: fixed isTextureBacked(), checked cc_unittests passes

Original change's description:
> Revert "Release YUVA planes in SkImage_GpuYUVA after flattenning to RGBA."
>
> This reverts commit a15f355be83136e7827ccfbc9bb9e9ea77f48518.
>
> Reason for revert: ANGLE failing new test
>
> Original change's description:
> > Release YUVA planes in SkImage_GpuYUVA after flattenning to RGBA.
> >
> > Also removed unused virtual function from SkImage_GpuBase and override
> > on SkImage_GpuYUVA.
> >
> > Change-Id: Ib47b46b529b16976181cb9453976133d66e0f952
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/212734
> > Commit-Queue: Brian Salomon <bsalomon@google.com>
> > Reviewed-by: Robert Phillips <robertphillips@google.com>
>
> TBR=jvanverth@google.com,bsalomon@google.com,robertphillips@google.com
>
> Change-Id: Ib2566ff8aa99d3698d6044167e70a1d75542f2e9
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/212986
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> Commit-Queue: Robert Phillips <robertphillips@google.com>

TBR=jvanverth@google.com,bsalomon@google.com,robertphillips@google.com

Change-Id: I3c9454da33a764504e768d02b59a5cd99766aff1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/212988
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
5 files changed