Reason for revert:
Breaks Ubuntu and Mac CMAKE
Original issue's description:
> Make SkPicture/SkImageGenerator default to SkCodec
>
> Remove reference to SkImageDecoder from SkPicture. Make the default
> InstallPixelRefProc passed to CreateFromStream use
> SkImageGenerator::NewFromEncoded instead.
>
> Make SkImageGenerator::NewFromEncoded create an SkCodecImageGenerator.
> Remove the old version that used SkImageDecoder.
>
> Remove all versions of lazy_decode_bitmap/LazyDecodeBitmap. The default
> now behaves lazily.
>
> Update all clients to use the default.
>
> Move SkImageDecoderGenerator into KtxTest.cpp, and use it directly.
>
> BUG=skia:4691
> BUG=skia:4290
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1671193002
>
> Committed: https://skia.googlesource.com/skia/+/026388a01864c74208ad57d1ba4f711602d101c6TBR=msarett@google.com,reed@google.com,scroggo@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4691
Review URL: https://codereview.chromium.org/1685963004
1de415f2c3