converted EllipseEffect to sksl

Bug: skia:
Change-Id: Id089b9ead7a21e903b001006dffff2381efd4ba3
Reviewed-on: https://skia-review.googlesource.com/23582
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/gn/gpu.gni b/gn/gpu.gni
index 33f8d67..f7160f0 100644
--- a/gn/gpu.gni
+++ b/gn/gpu.gni
@@ -316,6 +316,8 @@
   "$_src/gpu/effects/GrDistanceFieldGeoProc.h",
   "$_src/gpu/effects/GrDitherEffect.cpp",
   "$_src/gpu/effects/GrDitherEffect.h",
+  "$_src/gpu/effects/GrEllipseEffect.cpp",
+  "$_src/gpu/effects/GrEllipseEffect.h",
   "$_src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp",
   "$_src/gpu/effects/GrGaussianConvolutionFragmentProcessor.h",
   "$_src/gpu/effects/GrMatrixConvolutionEffect.cpp",