Virtually dispatched specialized scavengers.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index e79a5505c90db513ae3b18fbd25aa1931e9ff3a6..10c549c6b635ece1c9e081bf1ff6e1f49ff5395f 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -2190,6 +2190,8 @@ Object* JSObject::NormalizeProperties(PropertyNormalizationMode mode,
     int new_instance_size = map()->instance_size() - instance_size_delta;
     new_map->set_inobject_properties(0);
     new_map->set_instance_size(new_instance_size);
+    new_map->set_scavenger(Heap::GetScavenger(new_map->instance_type(),
+                                              new_map->instance_size()));
     Heap::CreateFillerObjectAt(this->address() + new_instance_size,
                                instance_size_delta);
   }