How can I access Chrome's spell-check dictionary?

Clearly Chrome has a built-in dictionary that it uses for spell-checking. Is there an API or some way to access this dictionary? I am interested not in checking spelling, but actually accessing the dictionary. E.g. I would like to write Dictionary autocomplete extension for chrome? a dictionary autocomplete extension that uses Chrome's dictionary instead of maintaining my own. Of particular interest to me would be a funciton like getWordsThatStartWith(text).