Perform color correction on png decodes

src/core/SkNx.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkNx_DEFINED
 #define SkNx_DEFINED
 
@@ skipping 148 matching lines @@
     static SkNx Max(const SkNx& x, const SkNx& y) { return x.fVal > y.fVal ? x : y; }
 
     SkNx saturatedAdd(const SkNx& y) const {
         static_assert(std::is_unsigned<T>::value, "");
         T sum = fVal + y.fVal;
         return sum < fVal ? std::numeric_limits<T>::max() : sum;
     }
 
     SkNx thenElse(const SkNx& t, const SkNx& e) const { return fVal != 0 ? t : e; }
 
+    SkNx logicalShiftRight(int bits) const { return ((unsigned) fVal) >> bits; }
+
 private:
     // Helper functions to choose the right float/double methods.  (In <cmath> madness lies...)
     static float   Abs(float val) { return  ::fabsf(val); }
     static float  Sqrt(float val) { return  ::sqrtf(val); }
     static float Floor(float val) { return ::floorf(val); }
 
     static double   Abs(double val) { return  ::fabs(val); }
     static double  Sqrt(double val) { return  ::sqrt(val); }
     static double Floor(double val) { return ::floor(val); }
 
@@ skipping 141 matching lines @@
 
 #endif
 
 SI void Sk4f_ToBytes(uint8_t p[16], const Sk4f& a, const Sk4f& b, const Sk4f& c, const Sk4f& d) {
     SkNx_cast<uint8_t>(SkNx_join(SkNx_join(a,b), SkNx_join(c,d))).store(p);
 }
 
 #undef SI
 
 #endif//SkNx_DEFINED