Add gammaIsLinear() API to SkColorSpace

include/core/SkColorSpace.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_DEFINED
 #define SkColorSpace_DEFINED
 
@@ skipping 57 matching lines @@
     /**
      *  Create an SkColorSpace from an ICC profile.
      */
     static sk_sp<SkColorSpace> NewICC(const void*, size_t);
 
     /**
      *  Create an SkColorSpace with the same gamut as this color space, but with linear gamma.
      */
     sk_sp<SkColorSpace> makeLinearGamma();
 
+    /**
+     *  DO NOT USE: Will be deleted.
+     */
     GammaNamed gammaNamed() const { return fGammaNamed; }
 
     /**
      *  Returns the matrix used to transform src gamut to XYZ D50.
      */
     const SkMatrix44& xyz() const { return fToXYZD50; }
 
     /**
      *  Returns true if the color space gamma is near enough to be approximated as sRGB.
      */
     bool gammaCloseToSRGB() const {
         return kSRGB_GammaNamed == fGammaNamed || k2Dot2Curve_GammaNamed == fGammaNamed;
     }
 
     /**
-     *  To be used only by UMA code.
+     *  Returns true if the color space gamma is linear.
      */
-    bool gammasAreMatching() const;
-    bool gammasAreNamed() const;
-    bool gammasAreValues() const;
-    bool gammasAreTables() const;
-    bool gammasAreParams() const;
+    bool gammaIsLinear() const {
+        return kLinear_GammaNamed == fGammaNamed;
+    }
 
     /**
      *  Returns nullptr on failure.  Fails when we fallback to serializing ICC data and
      *  the data is too large to serialize.
      */
     sk_sp<SkData> serialize() const;
 
     /**
      *  If |memory| is nullptr, returns the size required to serialize.
      *  Otherwise, serializes into |memory| and returns the size.
      */
     size_t writeToMemory(void* memory) const;
 
     static sk_sp<SkColorSpace> Deserialize(const void* data, size_t length);
 
     /**
      *  If both are null, we return true.  If one is null and the other is not, we return false.
      *  If both are non-null, we do a deeper compare.
      */
     static bool Equals(const SkColorSpace* src, const SkColorSpace* dst);
 
 protected:
     SkColorSpace(GammaNamed gammaNamed, const SkMatrix44& toXYZD50);
 
     const GammaNamed fGammaNamed;
     const SkMatrix44 fToXYZD50;
 };
 
 #endif