Add NewRGB() with float gamma to SkColorSpace public API

src/core/SkColorSpace_Base.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkColorSpace_Base_DEFINED
 #define SkColorSpace_Base_DEFINED
 
@@ skipping 151 matching lines @@
 
     // Objects of this type are created in a custom fashion using sk_malloc_throw
     // and therefore must be sk_freed.
     void* operator new(size_t size) = delete;
     void* operator new(size_t, void* p) { return p; }
     void operator delete(void* p) { sk_free(p); }
 };
 
 class SkColorSpace_Base : public SkColorSpace {
 public:
-
-    static sk_sp<SkColorSpace> NewRGB(const float gammas[3], const SkMatrix44& toXYZD50);
-
     SkGammaNamed gammaNamed() const { return fGammaNamed; }
     const SkGammas* gammas() const { return fGammas.get(); }
 
     const SkColorLookUpTable* colorLUT() const { return fColorLUT.get(); }
 
     const SkMatrix44& toXYZD50() const { return fToXYZD50; }
     const SkMatrix44& fromXYZD50() const;
     
     /**
      *  Create an SkColorSpace with the same gamut as this color space, but with linear gamma.
@@ skipping 39 matching lines @@
 
 static inline const SkColorSpace_Base* as_CSB(const SkColorSpace* colorSpace) {
     return static_cast<const SkColorSpace_Base*>(colorSpace);
 }
 
 static inline SkColorSpace_Base* as_CSB(const sk_sp<SkColorSpace>& colorSpace) {
     return static_cast<SkColorSpace_Base*>(colorSpace.get());
 }
 
 #endif