Reland "[skottie] Add tritone layer effect support"

This reverts commit 42ee4028a9b8619157890ee0d9d60b02bcc84028.

Original change's description:
> Revert "[skottie] Add tritone layer effect support"
> 
> This reverts commit 71c70ea13e26814ba560f3f6b1398888b9a5f0b8.
> 
> Reason for revert: broke WASM builds
> 
> Original change's description:
> > [skottie] Add tritone layer effect support
> > 
> > Generalize sksg::TintColorFilter into GradientColorfilter, to support
> > multiple color interpolation ranges.
> > 
> > Keep the two-color/single-matrix (tint) specialization, and use a table
> > color filter for the general case.
> > 
> > Change-Id: Idf42833462127c29fb69fe94337a1d1478b77dd9
> > Reviewed-on: https://skia-review.googlesource.com/c/194024
> > Reviewed-by: Mike Reed <reed@google.com>
> > Commit-Queue: Florin Malita <fmalita@chromium.org>
> 
> TBR=fmalita@chromium.org,reed@google.com
> 
> Change-Id: Id5bd99701f74fbd4f54d0aca74e753b7ab88bdb3
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://skia-review.googlesource.com/c/194429
> Reviewed-by: Florin Malita <fmalita@chromium.org>
> Commit-Queue: Florin Malita <fmalita@chromium.org>

TBR=fmalita@chromium.org,reed@google.com

Change-Id: Ie7fc28ff784b91f01108415e50677e8982ccf858
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/194430
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
4 files changed