Revert of Remove gpu-specialization of SkSpecialImage (patchset #5 id:80001 of https...

Revert of Remove gpu-specialization of SkSpecialImage (patchset #5 id:80001 of https://codereview.chromium.org/1918993002/ )

Reason for revert:
N6 bot has gone red

Original issue's description:
> Remove gpu-specialization of SkSpecialImage
>
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1918993002
>
> Committed: https://skia.googlesource.com/skia/+/0533d6e4142c2787d6d3c325ef0d8d1962292cad

TBR=reed@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1921393003