Push isEqual/onIsEqual down from GrProcessor to subclasses.

R=joshualitt@google.com

Review URL: https://codereview.chromium.org/654273002
diff --git a/src/gpu/effects/GrTextureDomain.h b/src/gpu/effects/GrTextureDomain.h
index ec86847..6f56f91 100644
--- a/src/gpu/effects/GrTextureDomain.h
+++ b/src/gpu/effects/GrTextureDomain.h
@@ -173,7 +173,7 @@
                           GrTextureParams::FilterMode,
                           GrCoordSet);
 
-    virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE;
+    virtual bool onIsEqual(const GrFragmentProcessor&) const SK_OVERRIDE;
 
     virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE;