Refactored SkColorSpace and added in a Lab PCS GM

src/core/SkColorSpaceXform_Base.h

Index: src/core/SkColorSpaceXform_Base.h
diff --git a/src/core/SkColorSpaceXform_Base.h b/src/core/SkColorSpaceXform_Base.h
index 02714ad59ee4800a9c5960aafd0ef72283375b08..f5758294addab26c8ce6ce519892efc7b097b422 100644
--- a/src/core/SkColorSpaceXform_Base.h
+++ b/src/core/SkColorSpaceXform_Base.h
@@ -30,6 +30,8 @@ enum ColorSpaceMatch {
     kFull_ColorSpaceMatch,
 };
 
+class SkColorSpace_XYZTRC;
+
 template <SrcGamma kSrc, DstGamma kDst, ColorSpaceMatch kCSM>
 class SkColorSpaceXform_Base : public SkColorSpaceXform {
 public:
@@ -40,8 +42,8 @@ protected:
                  int count, SkAlphaType alphaType) const override;
 
 private:
-    SkColorSpaceXform_Base(SkColorSpace* srcSpace, const SkMatrix44& srcToDst,
-                           SkColorSpace* dstSpace);
+    SkColorSpaceXform_Base(SkColorSpace_XYZTRC* srcSpace, const SkMatrix44& srcToDst,
+                           SkColorSpace_XYZTRC* dstSpace);
 
     sk_sp<SkColorLookUpTable> fColorLUT;
 
@@ -53,10 +55,10 @@ private:
     float                     fSrcToDst[16];
 
     friend class SkColorSpaceXform;
-    friend std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(SkColorSpace* space);
+    friend std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(SkColorSpace_XYZTRC* space);
 };
 
 // For testing.  Bypasses opts for when src and dst color spaces are equal.
-std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(SkColorSpace* space);
+std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(SkColorSpace_XYZTRC* space);
 
 #endif