Return MaybeHandle from SetElement and DeleteElement.

src/handles.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 276 matching lines @@
 // an object of expected type, or the handle is an error if running out
 // of space or encountering an internal error.
 
 // Flattens a string.
 void FlattenString(Handle<String> str);
 
 // Flattens a string and returns the underlying external or sequential
 // string.
 Handle<String> FlattenGetString(Handle<String> str);
 
-Handle<Object> DeleteProperty(Handle<JSObject> object, Handle<Object> key);
-
-Handle<Object> ForceDeleteProperty(Handle<JSObject> object, Handle<Object> key);
-
-Handle<Object> HasProperty(Handle<JSReceiver> obj, Handle<Object> key);
-
 Handle<Object> GetProperty(Handle<JSReceiver> obj, const char* name);
 
 // Get the JS object corresponding to the given script; create it
 // if none exists.
 Handle<JSValue> GetScriptWrapper(Handle<Script> script);
 
 // Script line number computations. Note that the line number is zero-based.
 void InitScriptLineEnds(Handle<Script> script);
 // For string calculates an array of line end positions. If the string
 // does not end with a new line character, this character may optionally be
@@ skipping 57 matching lines @@
 
   void Initialize() {
     next = limit = NULL;
     level = 0;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HANDLES_H_