Refactored SkColorSpace and added in a Lab PCS GM

src/core/SkColorSpace_XYZ.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_XYZ_DEFINED
+#define SkColorSpace_XYZ_DEFINED
+
+#include "SkColorSpace_Base.h"
+#include "SkData.h"
+#include "SkOnce.h"
+
+class SkColorSpace_XYZ : public SkColorSpace_Base {
+public:
+    const SkMatrix44* toXYZD50() const override { return &fToXYZD50; }
+    
+    const SkMatrix44* fromXYZD50() const override;
+
+    bool onGammaCloseToSRGB() const override;
+    
+    bool onGammaIsLinear() const override;
+    
+    Type type() const override { return Type::kXYZ; }
+    
+    sk_sp<SkColorSpace> makeLinearGamma();
+    
+    SkGammaNamed gammaNamed() const { return fGammaNamed; }
+    
+    const SkGammas* gammas() const { return fGammas.get(); }
+    
+    void toDstGammaTables(const uint8_t* tables[3], sk_sp<SkData>* storage, int numTables) const;
+
+private:
+    SkColorSpace_XYZ(SkGammaNamed gammaNamed, const SkMatrix44& toXYZ);
+
+    SkColorSpace_XYZ(SkGammaNamed gammaNamed, sk_sp<SkGammas> gammas,
+                     const SkMatrix44& toXYZ, sk_sp<SkData> profileData);
+
+    const SkGammaNamed     fGammaNamed;
+    sk_sp<SkGammas>        fGammas;
+    const SkMatrix44       fToXYZD50;
+    
+    mutable SkMatrix44     fFromXYZD50;
+    mutable SkOnce         fFromXYZOnce;
+    
+    mutable sk_sp<SkData>  fDstStorage;
+    mutable const uint8_t* fToDstGammaTables[3];
+    mutable SkOnce         fToDstGammaOnce;
+
+    friend class SkColorSpace;
+    friend class SkColorSpace_Base;
+    friend class ColorSpaceXformTest;
+    typedef SkColorSpace_Base INHERITED;
+};
+
+#endif