Add special case circle blur for Ganesh

include/core/SkRRect.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkRRect_DEFINED
 #define SkRRect_DEFINED
 
@@ skipping 78 matching lines @@
         SkDEBUGCODE(this->validate();)
         return static_cast<Type>(fType);
     }
 
     Type type() const { return this->getType(); }
 
     inline bool isEmpty() const { return kEmpty_Type == this->getType(); }
     inline bool isRect() const { return kRect_Type == this->getType(); }
     inline bool isOval() const { return kOval_Type == this->getType(); }
     inline bool isSimple() const { return kSimple_Type == this->getType(); }
+    // TODO: should isSimpleCircular & isCircle take a tolerance? This could help
+    // instances where the mapping to device space is noisy.
     inline bool isSimpleCircular() const {
-        return this->isSimple() && fRadii[0].fX == fRadii[0].fY;
+        return this->isSimple() && SkScalarNearlyEqual(fRadii[0].fX, fRadii[0].fY);
+    }
+    inline bool isCircle() const {
+        return this->isOval() && SkScalarNearlyEqual(fRadii[0].fX, fRadii[0].fY);
     }
     inline bool isNinePatch() const { return kNinePatch_Type == this->getType(); }
     inline bool isComplex() const { return kComplex_Type == this->getType(); }
 
     bool allCornersCircular() const;
 
     SkScalar width() const { return fRect.width(); }
     SkScalar height() const { return fRect.height(); }
 
     /**
@@ skipping 22 matching lines @@
 
         SkDEBUGCODE(this->validate();)
     }
 
     static SkRRect MakeRect(const SkRect& r) {
         SkRRect rr;
         rr.setRect(r);
         return rr;
     }
     
+    static SkRRect MakeOval(const SkRect& oval) {
+        SkRRect rr;
+        rr.setOval(oval);
+        return rr;
+    }
+
     /**
      * Set this RR to match the supplied oval. All x radii will equal half the
      * width and all y radii will equal half the height.
      */
     void setOval(const SkRect& oval) {
         if (oval.isEmpty()) {
             this->setEmpty();
             return;
         }
 
@@ skipping 151 matching lines @@
     // uninitialized data
 
     void computeType();
     bool checkCornerContainment(SkScalar x, SkScalar y) const;
 
     // to access fRadii directly
     friend class SkPath;
 };
 
 #endif