allow more options for shader blitprocs

src/core/SkColorShader.h

 /*
  * Copyright 2007 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 SkColorShader_DEFINED
 #define SkColorShader_DEFINED
 
@@ skipping 18 matching lines @@
     class ColorShaderContext : public SkShader::Context {
     public:
         ColorShaderContext(const SkColorShader& shader, const ContextRec&);
 
         uint32_t getFlags() const override;
         void shadeSpan(int x, int y, SkPMColor span[], int count) override;
         void shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) override;
         void shadeSpan4f(int x, int y, SkPM4f[], int count) override;
 
     protected:
-        BlitProc onChooseBlitProc(const SkImageInfo&, BlitState*) override;
-    
+        bool onChooseBlitProcs(const SkImageInfo&, BlitState*) override;
+
     private:
         SkPM4f      fPM4f;
         SkPMColor   fPMColor;
         uint32_t    fFlags;
 
         typedef SkShader::Context INHERITED;
     };
 
     GradientType asAGradient(GradientInfo* info) const override;
 
@@ skipping 15 matching lines @@
         return true;
     }
 
 private:
     SkColor fColor;
 
     typedef SkShader INHERITED;
 };
 
 #endif