create struct to hold all the params passed around for shader::context

src/effects/gradients/SkGradientShaderPriv.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 SkGradientShaderPriv_DEFINED
 #define SkGradientShaderPriv_DEFINED
 
@@ skipping 124 matching lines @@
         static void initCache16(GradientShaderCache* cache);
         static void initCache32(GradientShaderCache* cache);
 
         static void Build16bitCache(uint16_t[], SkColor c0, SkColor c1, int count);
         static void Build32bitCache(SkPMColor[], SkColor c0, SkColor c1, int count,
                                     U8CPU alpha, uint32_t gradFlags);
     };
 
     class GradientShaderBaseContext : public SkShader::Context {
     public:
-        GradientShaderBaseContext(const SkGradientShaderBase& shader, const SkBitmap& device,
-                                  const SkPaint& paint, const SkMatrix& matrix);
-        ~GradientShaderBaseContext() {}
+        GradientShaderBaseContext(const SkGradientShaderBase& shader, const ContextRec&);
 
         virtual uint32_t getFlags() const SK_OVERRIDE { return fFlags; }
 
     protected:
         SkMatrix    fDstToIndex;
         SkMatrix::MapXYProc fDstToIndexProc;
         uint8_t     fDstToIndexClass;
         uint8_t     fFlags;
 
         SkAutoTUnref<GradientShaderCache> fCache;
@@ skipping 284 matching lines @@
     GrGLUniformManager::UniformHandle fColorStartUni;
     GrGLUniformManager::UniformHandle fColorMidUni;
     GrGLUniformManager::UniformHandle fColorEndUni;
 
     typedef GrGLEffect INHERITED;
 };
 
 #endif
 
 #endif