Fix memory leak caused by field type in descriptor array.

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 6425 matching lines @@
   void ZapTransitions();
 
   void DeprecateTransitionTree();
   bool DeprecateTarget(PropertyKind kind, Name* key,
                        PropertyAttributes attributes,
                        DescriptorArray* new_descriptors,
                        LayoutDescriptor* new_layout_descriptor);
 
   Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
 
+  // Update field type of the given descriptor to new representation and new
+  // type. The type must be prepared for storing in descriptor array:
+  // it must be either a simple type or a map wrapped in a weak cell.
   void UpdateFieldType(int descriptor_number, Handle<Name> name,
                        Representation new_representation,
-                       Handle<HeapType> new_type);
+                       Handle<Object> new_wrapped_type);
 
   void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
                             PropertyAttributes attributes);
   void PrintGeneralization(FILE* file,
                            const char* reason,
                            int modify_index,
                            int split,
                            int descriptors,
                            bool constant_to_field,
                            Representation old_representation,
@@ skipping 4526 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_