Revert "Fix GPU improved noise impl and add to perlinnoise GM."

This reverts commit bef02dca9da1d0c67e5653346c740cb099c1d0b8.

Reason for revert: PreAbandonGpuContext failing on tree

Original change's description:
> Fix GPU improved noise impl and add to perlinnoise GM.
>
> GPU was recently busted when switching alpha-color type swizzles from
> aaaa to 000a.
>
> There was no GM that exercised SkPerlinNoiseShader::MakeImprovedNoise.
>
> It draws wrong before and after this change with the CPU backend.
>
> Bug: skia:10536
> Change-Id: I514e304d022fcccae80699a99facafa8ce947e9f
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/350916
> Auto-Submit: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Greg Daniel <egdaniel@google.com>
> Reviewed-by: Greg Daniel <egdaniel@google.com>

TBR=egdaniel@google.com,bsalomon@google.com

Change-Id: Iac635028b402e6008e3a8050bdfa66052d94fd10
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:10536
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/350956
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2 files changed