Introduce GrColorSpaceXform, for gamut conversion on textures

src/effects/GrAlphaThresholdFragmentProcessor.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAlphaThresholdFragmentProcessor.h"
 
 #if SK_SUPPORT_GPU
@@ skipping 26 matching lines @@
 GrAlphaThresholdFragmentProcessor::GrAlphaThresholdFragmentProcessor(GrTexture* texture,
                                                                      GrTexture* maskTexture,
                                                                      float innerThreshold,
                                                                      float outerThreshold,
                                                                      const SkIRect& bounds)
     : fInnerThreshold(innerThreshold)
     , fOuterThreshold(outerThreshold)
     , fImageCoordTransform(kLocal_GrCoordSet,
                            GrCoordTransform::MakeDivByTextureWHMatrix(texture), texture,
                            GrTextureParams::kNone_FilterMode)
-    , fImageTextureAccess(texture)
+    , fImageTextureAccess(texture, nullptr)
     , fMaskCoordTransform(kLocal_GrCoordSet,
                           make_div_and_translate_matrix(maskTexture, -bounds.x(), -bounds.y()),
                           maskTexture,
                           GrTextureParams::kNone_FilterMode)
-    , fMaskTextureAccess(maskTexture) {
+    , fMaskTextureAccess(maskTexture, nullptr) {
     this->initClassID<GrAlphaThresholdFragmentProcessor>();
     this->addCoordTransform(&fImageCoordTransform);
     this->addTextureAccess(&fImageTextureAccess);
     this->addCoordTransform(&fMaskCoordTransform);
     this->addTextureAccess(&fMaskTextureAccess);
 }
 
 bool GrAlphaThresholdFragmentProcessor::onIsEqual(const GrFragmentProcessor& sBase) const {
     const GrAlphaThresholdFragmentProcessor& s = sBase.cast<GrAlphaThresholdFragmentProcessor>();
     return (this->fInnerThreshold == s.fInnerThreshold &&
@@ skipping 104 matching lines @@
 void GrAlphaThresholdFragmentProcessor::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
                                                               GrProcessorKeyBuilder* b) const {
     GrGLAlphaThresholdFragmentProcessor::GenKey(*this, caps, b);
 }
 
 GrGLSLFragmentProcessor* GrAlphaThresholdFragmentProcessor::onCreateGLSLInstance() const {
     return new GrGLAlphaThresholdFragmentProcessor;
 }
 
 #endif