Make GrShape track the winding direction and starting point for rrect types.

include/core/SkRRect.h

Index: include/core/SkRRect.h
diff --git a/include/core/SkRRect.h b/include/core/SkRRect.h
index 5564ce0d7ee9733f24e77c1466a42c384b20d6d4..d025412d646ddc7028ea1c9e80784122d5579839 100644
--- a/include/core/SkRRect.h
+++ b/include/core/SkRRect.h
@@ -141,12 +141,18 @@ public:
         SkDEBUGCODE(this->validate();)
     }
 
+    static SkRRect MakeEmpty() {
+        SkRRect rr;
+        rr.setEmpty();
+        return rr;
+    }
+
     static SkRRect MakeRect(const SkRect& r) {
         SkRRect rr;
         rr.setRect(r);
         return rr;
     }
-    
+
     static SkRRect MakeOval(const SkRect& oval) {
         SkRRect rr;
         rr.setOval(oval);