Add isSingleComponent bool to getConstantColorComponent

src/effects/SkDisplacementMapEffect.cpp

Index: src/effects/SkDisplacementMapEffect.cpp
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index 474d9a7dc8123f8eec5c76fd3bf5ae95d71f26d7..fbd84b73c5a109bda5969dcbe34e4d8d07e6e241 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -351,11 +351,12 @@ public:
     typedef GrGLDisplacementMapEffect GLProcessor;
     static const char* Name() { return "DisplacementMap"; }
 
-    virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
-
 private:
     virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE;
 
+    virtual void onGetConstantColorComponents(GrColor* color, uint32_t* validFlags,
+                                              bool* isSingleComponent) const SK_OVERRIDE;
+
     GrDisplacementMapEffect(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
                             SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
                             const SkVector& scale,
@@ -491,8 +492,8 @@ const GrBackendFragmentProcessorFactory& GrDisplacementMapEffect::getFactory() c
     return GrTBackendFragmentProcessorFactory<GrDisplacementMapEffect>::getInstance();
 }
 
-void GrDisplacementMapEffect::getConstantColorComponents(GrColor*,
-                                                         uint32_t* validFlags) const {
+void GrDisplacementMapEffect::onGetConstantColorComponents(GrColor*, uint32_t* validFlags,
+                                                           bool* isSingleComponent) const {
     // Any displacement offset bringing a pixel out of bounds will output a color of (0,0,0,0),
     // so the only way we'd get a constant alpha is if the input color image has a constant alpha
     // and no displacement offset push any texture coordinates out of bounds OR if the constant