There are a few non-standard javascript extensions to String and Object in the shell that can be removed now that we are running v8:

1) The non-standard Object.keySet() function can be removed in favor of the standardized Object.keys() available in v8.
2) The non-standard String#rtrim() function can be removed in favor of the standardized String#trimRight() available in v8.
3) The non-standard String#ltrim() function can be removed in favor of the standardized String#trimLeft() available in v8.