Function cef_write_json 

pub unsafe extern "C" fn cef_write_json(
    node: *mut _cef_value_t,
    options: cef_json_writer_options_t,
) -> cef_string_userfree_t

Generates a JSON string from the specified root |node| which should be a dictionary or list value. Returns an NULL string on failure. This function requires exclusive access to |node| including any underlying data.