Revert of Checking for valid colorType, alphaType, colorSpace in SkCodec (patchset #2 id:100001 of https://codereview.chromium.org/2319293003/ )

Reason for revert:
Broken perf bots

Original issue's description:
> Checking for valid colorType, alphaType, colorSpace in SkCodec
>
> * Refactor to share code between SkPngCodec and SkWebpCodec
> * Didn't end up sharing with SkJpegCodec but did refactor
>   that code a bit
> * Disallow conversions to F16 with non-linear color spaces
> * Fail to decode if we fail to create a SkColorSpaceXform
>   (should be an assert soon).  We used to fallback on a
>   legacy decode if we failed to create the transform.
> * A bunch of name changes
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2319293003
>
> Committed: https://skia.googlesource.com/skia/+/7a9900d6d34e437bb24beb5524a1f6488ae138c9

TBR=scroggo@google.com,brianosman@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/2328663002
14 files changed