attached uniform and varying handlers to GrMtlPipelineStateBuilder

Bug: skia:
Change-Id: I4e8d09052153fa10bf887f07b70abe37d0c7e884
Reviewed-on: https://skia-review.googlesource.com/145159
Commit-Queue: Timothy Liang <timliang@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/gn/gpu.gni b/gn/gpu.gni
index 6dcb891..7178147 100644
--- a/gn/gpu.gni
+++ b/gn/gpu.gni
@@ -636,6 +636,7 @@
   "$_src/gpu/mtl/GrMtlGpu.mm",
   "$_src/gpu/mtl/GrMtlGpuCommandBuffer.h",
   "$_src/gpu/mtl/GrMtlPipelineState.h",
+  "$_src/gpu/mtl/GrMtlPipelineState.mm",
   "$_src/gpu/mtl/GrMtlPipelineStateBuilder.h",
   "$_src/gpu/mtl/GrMtlPipelineStateBuilder.mm",
   "$_src/gpu/mtl/GrMtlRenderTarget.h",
@@ -648,8 +649,12 @@
   "$_src/gpu/mtl/GrMtlTextureRenderTarget.mm",
   "$_src/gpu/mtl/GrMtlTrampoline.h",
   "$_src/gpu/mtl/GrMtlTrampoline.mm",
+  "$_src/gpu/mtl/GrMtlUniformHandler.h",
+  "$_src/gpu/mtl/GrMtlUniformHandler.mm",
   "$_src/gpu/mtl/GrMtlUtil.h",
   "$_src/gpu/mtl/GrMtlUtil.mm",
+  "$_src/gpu/mtl/GrMtlVaryingHandler.h",
+  "$_src/gpu/mtl/GrMtlVaryingHandler.mm",
 ]
 
 skia_native_gpu_sources = [