Fix color blending for analytic shadows

Change-Id: I74e8c385a87a3f397b2df53679fcfd9120d82954
Reviewed-on: https://skia-review.googlesource.com/15645
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 8d76fae..3f200bb 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -191,6 +191,9 @@
     if (!glInterface) {
         return nullptr;
     }
+#ifdef USE_NSIGHT
+    const_cast<GrContextOptions&>(options).fSuppressPathRendering = true;
+#endif
     GrGLContext* glContext = GrGLContext::Create(glInterface.get(), options);
     if (glContext) {
         return new GrGLGpu(glContext, context);