Revert of Opt state takes a GP instead of a GeometryStage (patchset #18 id:1500001 of https://codereview.chromium.org/637003003/)

Reason for revert:
Revert because this may be causing a break in a chrome gpu test

Original issue's description:
> Opt state takes a GP instead of a GeometryStage
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/71856d520461ae025a0332aa0ce9735a096d9baf

TBR=bsalomon@google.com,egdaniel@google.com,danakj@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/647183002
add drawImageRect to lua, update sample

BUG=skia:
TBR=

Review URL: https://codereview.chromium.org/642353005