Use a table-based implementation of SkDefaultXform

src/core/SkColorSpace_Base.h

Index: src/core/SkColorSpace_Base.h
diff --git a/src/core/SkColorSpace_Base.h b/src/core/SkColorSpace_Base.h
index fc4f665e688c66f3aa3016d9f43615a45c573182..5911c85ed40e3c1c786b17e95c1eeacd667a2a08 100644
--- a/src/core/SkColorSpace_Base.h
+++ b/src/core/SkColorSpace_Base.h
@@ -81,6 +81,18 @@ struct SkGammaCurve {
         , fE(0.0f)
         , fF(0.0f)
     {}
+
+    inline bool operator==(const SkGammaCurve& that) const {
+        return (this->fNamed == that.fNamed) && (this->fValue == that.fValue) &&
+                (this->fTableSize == that.fTableSize) && (this->fTable == that.fTable) &&
+                (this->fG == that.fG) && (this->fA == that.fA) && (this->fB == that.fB) &&
+                (this->fC == that.fC) && (this->fD == that.fD) && (this->fE == that.fE) &&
+                (this->fF == that.fF);
+    }
+
+    inline bool operator!=(const SkGammaCurve& that) const {
+        return !(*this == that);
+    }
 };
 
 struct SkGammas : public SkRefCnt {
@@ -148,7 +160,7 @@ public:
 
     static sk_sp<SkColorSpace> NewRGB(float gammas[3], const SkMatrix44& toXYZD50);
 
-    const sk_sp<SkGammas>& gammas() const { return fGammas; }
+    SkGammas* gammas() const { return fGammas.get(); }
 
     SkColorLookUpTable* colorLUT() const { return fColorLUT.get(); }
 
@@ -173,6 +185,7 @@ private:
     sk_sp<SkData>                     fProfileData;
 
     friend class SkColorSpace;
+    friend class ColorSpaceXformTest;
     typedef SkColorSpace INHERITED;
 };