Revert of Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/)

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
 
 #include "SkGradientShader.h"
 #include "SkClampRange.h"
 #include "SkColorPriv.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkMallocPixelRef.h"
+#include "SkUnitMapper.h"
 #include "SkUtils.h"
 #include "SkTemplates.h"
 #include "SkBitmapCache.h"
 #include "SkShader.h"
 #include "SkOnce.h"
 
 static inline void sk_memset32_dither(uint32_t dst[], uint32_t v0, uint32_t v1,
                                int count) {
     if (count > 0) {
         if (v0 == v1) {
@@ skipping 59 matching lines @@
     struct Descriptor {
         Descriptor() {
             sk_bzero(this, sizeof(*this));
             fTileMode = SkShader::kClamp_TileMode;
         }
 
         const SkColor*      fColors;
         const SkScalar*     fPos;
         int                 fCount;
         SkShader::TileMode  fTileMode;
+        SkUnitMapper*       fMapper;
         uint32_t            fGradFlags;
     };
 
 public:
     SkGradientShaderBase(const Descriptor& desc, const SkMatrix* localMatrix);
     virtual ~SkGradientShaderBase();
 
     // The cache is initialized on-demand when getCache16/32 is called.
     class GradientShaderCache : public SkRefCnt {
     public:
@@ skipping 86 matching lines @@
     // also be filled with the gradient colors
     GpuColorType getGpuColorType(SkColor colors[3]) const;
 
     uint32_t getGradFlags() const { return fGradFlags; }
 
 protected:
     SkGradientShaderBase(SkReadBuffer& );
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
     SK_TO_STRING_OVERRIDE()
 
+    SkUnitMapper* fMapper;
     SkMatrix    fPtsToUnit;     // set by subclass
     TileMode    fTileMode;
     TileProc    fTileProc;
     int         fColorCount;
     uint8_t     fGradFlags;
 
     struct Rec {
         SkFixed     fPos;   // 0...1
         uint32_t    fScale; // (1 << 24) / range
     };
@@ skipping 225 matching lines @@
     GrGLUniformManager::UniformHandle fColorStartUni;
     GrGLUniformManager::UniformHandle fColorMidUni;
     GrGLUniformManager::UniformHandle fColorEndUni;
 
     typedef GrGLEffect INHERITED;
 };
 
 #endif
 
 #endif