Add onGetBlendInfo to GrXferProcessor

src/effects/SkArithmeticMode_gpu.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkArithmeticMode_gpu.h"
 
 #if SK_SUPPORT_GPU
@@ skipping 163 matching lines @@
     GrGLXferProcessor* createGLInstance() const override;
 
     bool hasSecondaryOutput() const override { return false; }
 
     GrXferProcessor::OptFlags getOptimizations(const GrProcOptInfo& colorPOI,
                                                const GrProcOptInfo& coveragePOI,
                                                bool doesStencilWrite,
                                                GrColor* overrideColor,
                                                const GrDrawTargetCaps& caps) override;
 
-    void getBlendInfo(GrXferProcessor::BlendInfo* blendInfo) const override {
-        blendInfo->fSrcBlend = kOne_GrBlendCoeff;
-        blendInfo->fDstBlend = kZero_GrBlendCoeff;
-        blendInfo->fBlendConstant = 0;
-    }
-
     float k1() const { return fK1; }
     float k2() const { return fK2; }
     float k3() const { return fK3; }
     float k4() const { return fK4; }
     bool enforcePMColor() const { return fEnforcePMColor; }
 
 private:
     ArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor,
                    const GrDeviceCoordTexture* dstCopy, bool willReadDstColor);
 
@@ skipping 133 matching lines @@
     float k1 = random->nextF();
     float k2 = random->nextF();
     float k3 = random->nextF();
     float k4 = random->nextF();
     bool enforcePMColor = random->nextBool();
 
     return GrArithmeticXPFactory::Create(k1, k2, k3, k4, enforcePMColor);
 }
 
 #endif