Added tree structure to GrGLFragmentProcessor, i.e. GL instances

src/effects/SkArithmeticMode_gpu.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkArithmeticMode_gpu_DEFINED
 #define SkArithmeticMode_gpu_DEFINED
 
@@ skipping 24 matching lines @@
                                        float k3, float k4, bool enforcePMColor,
                                        GrTexture* background) {
         return SkNEW_ARGS(GrArithmeticFP, (procDataManager, k1, k2, k3, k4, enforcePMColor,
                                            background));
     }
 
     ~GrArithmeticFP() override {};
 
     const char* name() const override { return "Arithmetic"; }
 
-    GrGLFragmentProcessor* createGLInstance() const override;
-
     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:
+    GrGLFragmentProcessor* onCreateGLInstance() const override;
+
     void onGetGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override;
 
     bool onIsEqual(const GrFragmentProcessor&) const override;
 
     void onComputeInvariantOutput(GrInvariantOutput* inout) const override;
 
     GrArithmeticFP(GrProcessorDataManager*, float k1, float k2, float k3, float k4,
                    bool enforcePMColor, GrTexture* background);
 
     float                       fK1, fK2, fK3, fK4;
@@ skipping 53 matching lines @@
     GR_DECLARE_XP_FACTORY_TEST;
 
     float                       fK1, fK2, fK3, fK4;
     bool                        fEnforcePMColor;
 
     typedef GrXPFactory INHERITED;
 };
 
 #endif
 #endif