Add GM that directly tests GrRRectEffect and add inverse fill version of effect.

src/gpu/GrClipMaskManager.cpp

Index: src/gpu/GrClipMaskManager.cpp
diff --git a/src/gpu/GrClipMaskManager.cpp b/src/gpu/GrClipMaskManager.cpp
index 90106fa7e02565c573ad9b1e2fc3e0607e8ad41c..9b95d33c5ab6a8aefc78ba30eba65c88bfecc5d6 100644
--- a/src/gpu/GrClipMaskManager.cpp
+++ b/src/gpu/GrClipMaskManager.cpp
@@ -192,7 +192,7 @@ bool GrClipMaskManager::setupClipping(const GrClipData* clipDataIn,
             }
         } else if (isAA && SkClipStack::Element::kRRect_Type == type && !rt->isMultisampled()) {
             const SkRRect& rrect = elements.tail()->getRRect();
-            effect.reset(GrRRectEffect::Create(rrect));
+            effect.reset(GrRRectEffect::Create(GrRRectEffect::kFillAA_EdgeType, rrect));
         } else if (isAA && SkClipStack::Element::kRect_Type == type && !rt->isMultisampled()) {
             // We only handle AA/non-MSAA rects here. Coverage effect AA isn't MSAA friendly and
             // non-AA rect clips are handled by the scissor.