Potentially optimize some GrGLEffects for known input color values

src/effects/gradients/SkTwoPointConicalGradient.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTwoPointConicalGradient.h"
 
 static int valid_divide(float numer, float denom, float* ratio) {
@@ skipping 328 matching lines @@
 class GrGLConical2Gradient : public GrGLGradientEffect {
 public:
 
     GrGLConical2Gradient(const GrBackendEffectFactory& factory, const GrDrawEffect&);
     virtual ~GrGLConical2Gradient() { }
 
     virtual void emitCode(GrGLShaderBuilder*,
                           const GrDrawEffect&,
                           EffectKey,
                           const char* outputColor,
-                          const char* inputColor,
+                          const GrGLSLExpr4& inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
 
     static EffectKey GenKey(const GrDrawEffect&, const GrGLCaps& caps);
 
 protected:
 
     UniformHandle fParamUni;
 
@@ skipping 134 matching lines @@
     , fCachedDiffRadius(-SK_ScalarMax) {
 
     const GrConical2Gradient& data = drawEffect.castEffect<GrConical2Gradient>();
     fIsDegenerate = data.isDegenerate();
 }
 
 void GrGLConical2Gradient::emitCode(GrGLShaderBuilder* builder,
                                     const GrDrawEffect&,
                                     EffectKey key,
                                     const char* outputColor,
-                                    const char* inputColor,
+                                    const GrGLSLExpr4& inputColor,
                                     const TransformedCoordsArray& coords,
                                     const TextureSamplerArray& samplers) {
     this->emitUniforms(builder, key);
     fParamUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
                                          kFloat_GrSLType, "Conical2FSParams", 6);
 
     SkString cName("c");
     SkString ac4Name("ac4");
     SkString dName("d");
     SkString qName("q");
@@ skipping 212 matching lines @@
     str->appendScalar(fCenter2.fY);
     str->append(") radius2: ");
     str->appendScalar(fRadius2);
     str->append(" ");
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif