converted LumaColorFilterEffect to sksl

Bug: skia:
Change-Id: I208984ec9ad357249ee1b2fe28477f1450b4b69d
Reviewed-on: https://skia-review.googlesource.com/67848
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/gn/gpu.gni b/gn/gpu.gni
index e67b2ac..185d6d8 100644
--- a/gn/gpu.gni
+++ b/gn/gpu.gni
@@ -347,6 +347,8 @@
   "$_src/gpu/effects/GrGaussianConvolutionFragmentProcessor.h",
   "$_src/gpu/effects/GrMatrixConvolutionEffect.cpp",
   "$_src/gpu/effects/GrMatrixConvolutionEffect.h",
+  "$_src/gpu/effects/GrLumaColorFilterEffect.cpp",
+  "$_src/gpu/effects/GrLumaColorFilterEffect.h",
   "$_src/gpu/effects/GrNonlinearColorSpaceXformEffect.cpp",
   "$_src/gpu/effects/GrNonlinearColorSpaceXformEffect.h",
   "$_src/gpu/effects/GrOverdrawFragmentProcessor.cpp",