Push isEqual/onIsEqual down from GrProcessor to subclasses.

src/effects/SkArithmeticMode.cpp

Index: src/effects/SkArithmeticMode.cpp
diff --git a/src/effects/SkArithmeticMode.cpp b/src/effects/SkArithmeticMode.cpp
index 7e0ca37ad26a5daf9e73711cd5010647c6ac7765..d3376033291e2b444874febc814e474ebfaa0715 100644
--- a/src/effects/SkArithmeticMode.cpp
+++ b/src/effects/SkArithmeticMode.cpp
@@ -296,7 +296,7 @@ public:
     bool enforcePMColor() const { return fEnforcePMColor; }
 
 private:
-    virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE;
+    virtual bool onIsEqual(const GrFragmentProcessor&) const SK_OVERRIDE;
 
     virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE;
 
@@ -330,7 +330,7 @@ GrArithmeticEffect::GrArithmeticEffect(float k1, float k2, float k3, float k4,
 GrArithmeticEffect::~GrArithmeticEffect() {
 }
 
-bool GrArithmeticEffect::onIsEqual(const GrProcessor& sBase) const {
+bool GrArithmeticEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
     const GrArithmeticEffect& s = sBase.cast<GrArithmeticEffect>();
     return fK1 == s.fK1 &&
            fK2 == s.fK2 &&