Revert of Multi-string shaders (patchset #4 id:60001 of https://codereview.chromium.org/929503002/)

Reason for revert:
windows warnings

Original issue's description:
> Multi-string shaders
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/1c3c2d83364ee228e0751df0e1b9c161c0ba8c1e

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

Review URL: https://codereview.chromium.org/924973002
14 files changed