Reduce stencil buffer clearing

TBR=bsalomon@google.com
Bug: skia:6953
Change-Id: I079f90711297ee290f2d4011cfcb18b764554deb
Reviewed-on: https://skia-review.googlesource.com/40691
Reviewed-by: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/gn/gpu.gni b/gn/gpu.gni
index 2850972..acfd921 100644
--- a/gn/gpu.gni
+++ b/gn/gpu.gni
@@ -403,6 +403,7 @@
   "$_src/gpu/gl/GrGLGLSL.h",
   "$_src/gpu/gl/GrGLGpu.cpp",
   "$_src/gpu/gl/GrGLGpu.h",
+  "$_src/gpu/gl/GrGLGpuCommandBuffer.cpp",
   "$_src/gpu/gl/GrGLGpuCommandBuffer.h",
   "$_src/gpu/gl/GrGLGpuProgramCache.cpp",
   "$_src/gpu/gl/GrGLExtensions.cpp",