Add SkSourceGammaTreatment enum so we know how to create mips

experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPerlinNoiseShader2_DEFINED
 #define SkPerlinNoiseShader2_DEFINED
 
@@ skipping 89 matching lines @@
                          const StitchData& stitchData, const SkPoint& noiseVector) const;
 
         SkMatrix fMatrix;
         PaintingData* fPaintingData;
 
         typedef SkShader::Context INHERITED;
     };
 
 #if SK_SUPPORT_GPU
     const GrFragmentProcessor* asFragmentProcessor(GrContext* context, const SkMatrix& viewM,
-                                                   const SkMatrix*, SkFilterQuality) const override;
+                                                   const SkMatrix*, SkFilterQuality,
+                                                   SkSourceGammaTreatment) const override;
 #endif
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPerlinNoiseShader2)
 
 protected:
     void flatten(SkWriteBuffer&) const override;
     size_t onContextSize(const ContextRec&) const override;
     Context* onCreateContext(const ContextRec&, void* storage) const override;
 
 private:
     SkPerlinNoiseShader2(SkPerlinNoiseShader2::Type type, SkScalar baseFrequencyX,
                         SkScalar baseFrequencyY, int numOctaves, SkScalar seed,
                         const SkISize* tileSize);
     virtual ~SkPerlinNoiseShader2();
 
     const SkPerlinNoiseShader2::Type fType;
     const SkScalar                  fBaseFrequencyX;
     const SkScalar                  fBaseFrequencyY;
     const int                       fNumOctaves;
     const SkScalar                  fSeed;
     const SkISize                   fTileSize;
     const bool                      fStitchTiles;
 
     typedef SkShader INHERITED;
 };
 
 #endif