Reland "Add support for uniforms and layout(key)s to DSLCPPCodeGenerator."

This reverts commit 289da86e37c3ebfb121832174c46757012ca49c3.

Reason for revert: relanding

Original change's description:
> Revert "Add support for uniforms and layout(key)s to DSLCPPCodeGenerator."
>
> This reverts commit f33b061e3bebdecd8e9de41dffc6b8ce9d4e917a.
>
> Reason for revert: Google3 roll and wasm build
>
> Original change's description:
> > Add support for uniforms and layout(key)s to DSLCPPCodeGenerator.
> >
> > Change-Id: I77c386e3d72fb4a5986e5efb8bc9d409200534d1
> > Bug: skia:11854
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/398457
> > Commit-Queue: John Stiles <johnstiles@google.com>
> > Auto-Submit: John Stiles <johnstiles@google.com>
> > Reviewed-by: Brian Osman <brianosman@google.com>
>
> TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
>
> Change-Id: I006ece639fa6051ff6ef1c496e648db9d5d0b30a
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: skia:11854
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/399498
> Reviewed-by: John Stiles <johnstiles@google.com>
> Commit-Queue: John Stiles <johnstiles@google.com>


Bug: skia:11854
Change-Id: I1a4a4db471e2ad0b169b2b77784ca17e6286fbd2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/400036
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
14 files changed