Merged: Squashed multiple commits.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index b76af77d9e0388834359d5cc19f8a25d97c7e51c..a521bc3fe940d84b62b07406a4c1af6f50d642cc 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2353,6 +2353,11 @@ class JSObject: public JSReceiver {
   static bool UnregisterPrototypeUser(Handle<Map> user, Isolate* isolate);
   static void InvalidatePrototypeChains(Map* map);
 
+  // Updates prototype chain tracking information when an object changes its
+  // map from |old_map| to |new_map|.
+  static void NotifyMapChange(Handle<Map> old_map, Handle<Map> new_map,
+                              Isolate* isolate);
+
   // Utility used by many Array builtins and runtime functions
   static inline bool PrototypeHasNoElements(Isolate* isolate, JSObject* object);