Introduce GrColorSpaceXform, for gamut conversion on textures

src/effects/SkDisplacementMapEffect.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDisplacementMapEffect.h"
 
 #include "SkBitmap.h"
@@ skipping 448 matching lines @@
 GrDisplacementMapEffect::GrDisplacementMapEffect(
                              SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
                              SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
                              const SkVector& scale,
                              GrTexture* displacement,
                              const SkMatrix& offsetMatrix,
                              GrTexture* color,
                              const SkISize& colorDimensions)
     : fDisplacementTransform(kLocal_GrCoordSet, offsetMatrix, displacement,
                              GrTextureParams::kNone_FilterMode)
-    , fDisplacementAccess(displacement)
+    , fDisplacementAccess(displacement, nullptr)
     , fColorTransform(kLocal_GrCoordSet, color, GrTextureParams::kNone_FilterMode)
     , fDomain(GrTextureDomain::MakeTexelDomain(color, SkIRect::MakeSize(colorDimensions)),
               GrTextureDomain::kDecal_Mode)
-    , fColorAccess(color)
+    , fColorAccess(color, nullptr /* COLORXFORMTODO */)
     , fXChannelSelector(xChannelSelector)
     , fYChannelSelector(yChannelSelector)
     , fScale(scale) {
     this->initClassID<GrDisplacementMapEffect>();
     this->addCoordTransform(&fDisplacementTransform);
     this->addTextureAccess(&fDisplacementAccess);
     this->addCoordTransform(&fColorTransform);
     this->addTextureAccess(&fColorAccess);
 }
 
@@ skipping 133 matching lines @@
 void GrGLDisplacementMapEffect::GenKey(const GrProcessor& proc,
                                        const GrGLSLCaps&, GrProcessorKeyBuilder* b) {
     const GrDisplacementMapEffect& displacementMap = proc.cast<GrDisplacementMapEffect>();
 
     uint32_t xKey = displacementMap.xChannelSelector();
     uint32_t yKey = displacementMap.yChannelSelector() << kChannelSelectorKeyBits;
 
     b->add32(xKey | yKey);
 }
 #endif