Have VisitorHelper<> handle moving object registration.

third_party/WebKit/Source/platform/heap/MarkingVisitor.h

Index: third_party/WebKit/Source/platform/heap/MarkingVisitor.h
diff --git a/third_party/WebKit/Source/platform/heap/MarkingVisitor.h b/third_party/WebKit/Source/platform/heap/MarkingVisitor.h
index 926f4e0a692971246d29b81b1393fd46e068d796..9a07e69b891872cf05145db3e94d3b493e08a1e5 100644
--- a/third_party/WebKit/Source/platform/heap/MarkingVisitor.h
+++ b/third_party/WebKit/Source/platform/heap/MarkingVisitor.h
@@ -47,16 +47,6 @@ class MarkingVisitor final : public Visitor,
   }
 #endif
 
-  void registerMovingObjectReference(MovableReference* slot) override {
-    Impl::registerMovingObjectReference(slot);
-  }
-
-  void registerMovingObjectCallback(MovableReference backingStore,
-                                    MovingObjectCallback callback,
-                                    void* callbackData) override {
-    Impl::registerMovingObjectCallback(backingStore, callback, callbackData);
-  }
-
   bool ensureMarked(const void* objectPointer) override {
     return Impl::ensureMarked(objectPointer);
   }