Virtually dispatched specialized scavengers.

src/serialize.cc

Index: src/serialize.cc
diff --git a/src/serialize.cc b/src/serialize.cc
index a6a516a76d5ceb5896c47eb8bb4e76e282fd5659..e8aed5496f14dd0061760b3c20c60e2e32ebe19c 100644
--- a/src/serialize.cc
+++ b/src/serialize.cc
@@ -673,6 +673,14 @@ void Deserializer::ReadObject(int space_number,
     LOG(SnapshotPositionEvent(address, source_->position()));
   }
   ReadChunk(current, limit, space_number, address);
+
+  if (space == Heap::map_space()) {
+    ASSERT(size == Map::kSize);
+    HeapObject* obj = HeapObject::FromAddress(address);
+    Map* map = reinterpret_cast<Map*>(obj);
+    map->set_scavenger(Heap::GetScavenger(map->instance_type(),
+                                          map->instance_size()));
+  }
 }