Don't create new maps in CurrentMapForDeprecated.

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5359 matching lines @@
   inline bool owns_descriptors();
   inline void set_owns_descriptors(bool is_shared);
   inline bool is_observed();
   inline void set_is_observed(bool is_observed);
   inline void deprecate();
   inline bool is_deprecated();
   inline bool CanBeDeprecated();
   // Returns a non-deprecated version of the input. If the input was not
   // deprecated, it is directly returned. Otherwise, the non-deprecated version
   // is found by re-transitioning from the root of the transition tree using the
-  // descriptor array of the map. New maps (and transitions) may be created if
-  // no new (more general) version exists.
-  static inline Handle<Map> CurrentMapForDeprecated(Handle<Map> map);
+  // descriptor array of the map. Returns NULL if no updated map is found.
+  Map* CurrentMapForDeprecated();
 
   MUST_USE_RESULT MaybeObject* RawCopy(int instance_size);
   MUST_USE_RESULT MaybeObject* CopyWithPreallocatedFieldDescriptors();
   MUST_USE_RESULT MaybeObject* CopyDropDescriptors();
   MUST_USE_RESULT MaybeObject* CopyReplaceDescriptors(
       DescriptorArray* descriptors,
       Name* name,
       TransitionFlag flag,
       int descriptor_index);
   MUST_USE_RESULT MaybeObject* CopyInstallDescriptors(
@@ skipping 4215 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_