Implement color filter as GrGLEffect

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 "SkFlattenableBuffers.h"
 #include "SkUnPreMultiply.h"
@@ skipping 330 matching lines @@
     , fDisplacementAccess(displacement)
     , fColorTransform(kLocal_GrCoordSet, color)
     , fColorAccess(color)
     , fXChannelSelector(xChannelSelector)
     , fYChannelSelector(yChannelSelector)
     , fScale(scale) {
     this->addCoordTransform(&fDisplacementTransform);
     this->addTextureAccess(&fDisplacementAccess);
     this->addCoordTransform(&fColorTransform);
     this->addTextureAccess(&fColorAccess);
+    this->setWillNotUseInputColor();
 }
 
 GrDisplacementMapEffect::~GrDisplacementMapEffect() {
 }
 
 bool GrDisplacementMapEffect::onIsEqual(const GrEffect& sBase) const {
     const GrDisplacementMapEffect& s = CastEffect<GrDisplacementMapEffect>(sBase);
     return fDisplacementAccess.getTexture() == s.fDisplacementAccess.getTexture() &&
            fColorAccess.getTexture() == s.fColorAccess.getTexture() &&
            fXChannelSelector == s.fXChannelSelector &&
@@ skipping 145 matching lines @@
                                                         const GrGLCaps&) {
     const GrDisplacementMapEffect& displacementMap =
         drawEffect.castEffect<GrDisplacementMapEffect>();
 
     EffectKey xKey = displacementMap.xChannelSelector();
     EffectKey yKey = displacementMap.yChannelSelector() << SkDisplacementMapEffect::kKeyBits;
 
     return xKey | yKey;
 }
 #endif