Add effect-based clip for nine-patch SkRRects.

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 85 matching lines @@
     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(); }
     inline bool isSimpleCircular() const {
         return this->isSimple() && fRadii[0].fX == fRadii[0].fY;
     }
     inline bool isComplex() const { return kComplex_Type == this->getType(); }
 
     bool allCornersCircular() const;
 
+    /**
+     * Are both x-radii the same on the two left corners, and similar for the top, right, and
+     * bottom. When this is the case the four ellipse centers form a rectangle.
+     */
+    bool isNinePatch() const {
+        return fRadii[kUpperLeft_Corner].fX == fRadii[kLowerLeft_Corner].fX &&
+               fRadii[kUpperRight_Corner].fX == fRadii[kLowerRight_Corner].fX &&
+               fRadii[kUpperLeft_Corner].fY == fRadii[kUpperRight_Corner].fY &&
+               fRadii[kLowerLeft_Corner].fY == fRadii[kLowerRight_Corner].fY;
+    }
+
     SkScalar width() const { return fRect.width(); }
     SkScalar height() const { return fRect.height(); }
 
     /**
      * Set this RR to the empty rectangle (0,0,0,0) with 0 x & y radii.
      */
     void setEmpty() {
         fRect.setEmpty();
         memset(fRadii, 0, sizeof(fRadii));
         fType = kEmpty_Type;
@@ skipping 170 matching lines @@
     // uninitialized data
 
     void computeType() const;
     bool checkCornerContainment(SkScalar x, SkScalar y) const;
 
     // to access fRadii directly
     friend class SkPath;
 };
 
 #endif