Add shader-based GaussianEdgeShader for reveal case

src/ports/SkGlobalInitialization_default.cpp

Index: src/ports/SkGlobalInitialization_default.cpp
diff --git a/src/ports/SkGlobalInitialization_default.cpp b/src/ports/SkGlobalInitialization_default.cpp
index 1f1973649cef5b779927fe70dedf154e0fad2780..ed8b0e15ff85a3e603b604520a95680708eecc34 100644
--- a/src/ports/SkGlobalInitialization_default.cpp
+++ b/src/ports/SkGlobalInitialization_default.cpp
@@ -25,6 +25,7 @@
 #include "SkDropShadowImageFilter.h"
 #include "SkEmbossMaskFilter.h"
 #include "SkGaussianEdgeShader.h"
+#include "SkRRectsGaussianEdgeShader.h"
 #include "SkGradientShader.h"
 #include "SkImageSource.h"
 #include "SkLayerDrawLooper.h"
@@ -91,6 +92,7 @@ void SkFlattenable::PrivateInitializer::InitEffects() {
     SkLightingShader::InitializeFlattenables();
     SkNormalSource::InitializeFlattenables();
     SkGaussianEdgeShader::InitializeFlattenables();
+    SkRRectsGaussianEdgeShader::InitializeFlattenables();
 
     // PathEffect
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkArcToPathEffect)