add shadermaskfilter

next steps:
- gpu impl (will look a lot like shader's asFragProcessor
- special-case rect-input (?)
- explore stages w/ mtklein

Bug: skia:7500
Change-Id: I71089e421d32443a3ddded6967b3e5bc67ed43f2
Reviewed-on: https://skia-review.googlesource.com/95104
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Reviewed-by: Brian Salomon <bsalomon@google.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/gn/gm.gni b/gn/gm.gni
index 38aaff3fa8..a19d4074aa 100644
--- a/gn/gm.gni
+++ b/gn/gm.gni
@@ -263,6 +263,7 @@ gm_sources = [
   "$_gm/samplerstress.cpp",
   "$_gm/savelayer.cpp",
   "$_gm/scaledstrokes.cpp",
+  "$_gm/shadermaskfilter.cpp",
   "$_gm/shadertext.cpp",
   "$_gm/shadertext2.cpp",
   "$_gm/shadertext3.cpp",