Revert of Progress on gamma-correctness in the GPU backend. Fixed conversion of color and profile type to pix… (patchset #1 id:1 of https://codereview.chromium.org/1750383002/ )

Reason for revert:
GM breakage. Changes to SkGr.cpp appear to be altering behavior on a variety of tests. Debugging...

Original issue's description:
> Progress on gamma-correctness in the GPU backend. Fixed conversion of color and profile type to pixel config, which makes many things "just work".
>
> Added (color=8888|f16|srgb) option to gpu configurations, along with gpuf16, gpusrgb, and anglesrgb predefined configs. Runs the gpu backend in gamma-correct mode (with either FP16 linear or sRGB 8888 frambuffers).
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1750383002
>
> Committed: https://skia.googlesource.com/skia/+/a6f58194733c1c50e4fe5f98585e42344f29b6f0

TBR=mtklein@google.com,bsalomon@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1755553003
7 files changed