Use a table-based implementation of SkDefaultXform

src/core/SkColorSpaceXform.h

Index: src/core/SkColorSpaceXform.h
diff --git a/src/core/SkColorSpaceXform.h b/src/core/SkColorSpaceXform.h
index e6abdbb9924819834d2d345cc733f61b4769b855..91c1d61e359cfe360758f3c434ec3c05143224c3 100644
--- a/src/core/SkColorSpaceXform.h
+++ b/src/core/SkColorSpaceXform.h
@@ -57,15 +57,22 @@ public:
     void xform_RGB1_8888(uint32_t* dst, const uint32_t* src, uint32_t len) const override;
 
 private:
-    SkDefaultXform(const sk_sp<SkGammas>& srcGammas, const SkMatrix44& srcToDst,
-                   const sk_sp<SkGammas>& dstGammas);
+    SkDefaultXform(const sk_sp<SkColorSpace>& srcSpace, const SkMatrix44& srcToDst,
+                   const sk_sp<SkColorSpace>& dstSpace);
+
+    static constexpr int kDstGammaTableSize = 1024;
+
+    // May contain pointers into storage or pointers into precomputed tables.
+    float*           fSrcGammaTables[3];

[mtklein_C, 2016/06/21 20:32:52]

const float* for these pointers?  Presumably we're not going to be changing
those precomputed tables...

[msarett, 2016/06/21 21:24:47]

Done.

+    float            fSrcGammaTableStorage[3 * 256];
 
-    sk_sp<SkGammas>  fSrcGammas;
     const SkMatrix44 fSrcToDst;
-    sk_sp<SkGammas>  fDstGammas;
+
+    // May contain pointers into storage or pointers into precomputed tables.
+    uint8_t*         fDstGammaTables[3];
+    uint8_t          fDstGammaTableStorage[3 * kDstGammaTableSize];
 
     friend class SkColorSpaceXform;
-    friend class ColorSpaceXformTest;
 };
 
 #endif