Add isSingleComponent bool to getConstantColorComponent

src/effects/gradients/SkGradientShaderPriv.h

Index: src/effects/gradients/SkGradientShaderPriv.h
diff --git a/src/effects/gradients/SkGradientShaderPriv.h b/src/effects/gradients/SkGradientShaderPriv.h
index b81b5626ba83ba44b92bc8c8045082d4dc94fa4d..33d8adde055dde6ee0fa85a506ec1a5c84cfa244 100644
--- a/src/effects/gradients/SkGradientShaderPriv.h
+++ b/src/effects/gradients/SkGradientShaderPriv.h
@@ -342,8 +342,6 @@ public:
     bool useAtlas() const { return SkToBool(-1 != fRow); }
     SkScalar getYCoord() const { return fYCoord; };
 
-    virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
-
     SkGradientShaderBase::GpuColorType getColorType() const { return fColorType; }
 
     enum PremulType {
@@ -376,6 +374,8 @@ protected:
 
     virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE;
 
+    virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE;
+
     const GrCoordTransform& getCoordTransform() const { return fCoordTransform; }
 
 private: