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>
3 files changed