Prepare DefinePropertyAccessor for callback transitions.

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 2168 matching lines @@
       PropertyAttributes attributes);
   MUST_USE_RESULT MaybeObject* SetPropertyCallback(
       String* name,
       Object* structure,
       PropertyAttributes attributes);
   MUST_USE_RESULT MaybeObject* DefineElementAccessor(
       uint32_t index,
       Object* getter,
       Object* setter,
       PropertyAttributes attributes);
+  MUST_USE_RESULT MaybeObject* CreateAccessorPairFor(String* name);
   MUST_USE_RESULT MaybeObject* DefinePropertyAccessor(
       String* name,
       Object* getter,
       Object* setter,
       PropertyAttributes attributes);
   void LookupInDescriptor(String* name, LookupResult* result);
 
   // Returns the hidden properties backing store object, currently
   // a StringDictionary, stored on this object.
   // If no hidden properties object has been put on this object,
@@ skipping 6395 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_