Create blurred RRect mask on GPU (rather than uploading it)

include/effects/SkBlurMaskFilter.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBlurMaskFilter_DEFINED
 #define SkBlurMaskFilter_DEFINED
 
@@ skipping 47 matching lines @@
     static SkMaskFilter* CreateEmboss(SkScalar blurSigma, const SkScalar direction[3],
                                       SkScalar ambient, SkScalar specular) {
         return MakeEmboss(blurSigma, direction, ambient, specular).release();
     }
     SK_ATTR_DEPRECATED("use sigma version")
     static SkMaskFilter* CreateEmboss(const SkScalar direction[3],
                                       SkScalar ambient, SkScalar specular,
                                       SkScalar blurRadius);
 #endif
 
+    static bool ComputeBlurredRRectParams(const SkRRect& rrect,
+                                          SkScalar sigma,
+                                          SkRRect* rrectToDraw,
+                                          SkISize* widthHeight,
+                                          SkScalar xs[4],
+                                          int* numXs,
+                                          SkScalar ys[4],
+                                          int* numYs);
+
+
     SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
 
 private:
     SkBlurMaskFilter(); // can't be instantiated
 };
 
 #endif