Revert of Create an SkCodecImageGenerator (patchset #10 id:260001 of https://codereview.chromium.org/1487683004/ )

Reason for revert:
Core doesn't know about Codec.

Original issue's description:
> Create an SkCodecImageGenerator
>
> BUG=skia:
>
> patch from issue 1396323007 at patchset 120001 (http://crrev.com/1396323007#ps120001)
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1487683004
>
> Committed: https://skia.googlesource.com/skia/+/e1102ce1d3d0895e840e756e155ec56b5a1a7540

TBR=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:

Review URL: https://codereview.chromium.org/1582373003
5 files changed