Overwrite the handler using Set.

src/list.h

 // Copyright 2011 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 97 matching lines @@
               AllocationPolicy allocator = AllocationPolicy());
 
   // Add all the elements from the vector to this list.
   void AddAll(const Vector<T>& other,
               AllocationPolicy allocator = AllocationPolicy());
 
   // Inserts the element at the specific index.
   void InsertAt(int index, const T& element,
                 AllocationPolicy allocator = AllocationPolicy());
 
+  // Overwrites the element at the specific index.
+  void Set(int index, const T& element);
+
   // Added 'count' elements with the value 'value' and returns a
   // vector that allows access to the elements.  The vector is valid
   // until the next change is made to this list.
   Vector<T> AddBlock(T value, int count,
                      AllocationPolicy allocator = AllocationPolicy());
 
   // Removes the i'th element without deleting it even if T is a
   // pointer type; moves all elements above i "down". Returns the
   // removed element.  This function's complexity is linear in the
   // size of the list.
@@ skipping 81 matching lines @@
 template <typename T, class P>
 int SortedListBSearch(const List<T>& list, P cmp);
 template <typename T>
 int SortedListBSearch(const List<T>& list, T elem);
 
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_LIST_H_