Simple BlinkGC heap compaction.

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 516ac19dfab814149dfd372b90a37d8651a2898d..b5eb0b471e65792c626ff4ba84395fa46876ceb7 100644
--- a/third_party/WebKit/Source/platform/heap/MarkingVisitor.h
+++ b/third_party/WebKit/Source/platform/heap/MarkingVisitor.h
@@ -48,6 +48,16 @@ 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);
   }