During upgrade to the Chromium 61 we have switched from GTK2 to GTK3
and now we have a few warnings about stuff being deprecated in GTK3.
Check any Linux build to get a list of them.

/cc @zcbenz 
atom/browser/ui/file_dialog_gtk.cc
const gchar* filename) const {
  base::FilePath path(filename);
  GtkFileFilter* selected_filter =
      gtk_file_chooser_get_filter(GTK_FILE_CHOOSER(dialog_));
  if (!selected_filter)
    return path;
  GSList* filters = gtk_file_chooser_list_filters(GTK_FILE_CHOOSER(dialog_));
  int i = g_slist_index(filters, selected_filter);
  g_slist_free(filters);
  if (i >= filters_.size())
    return path;
  const auto& extensions = filters_[i].second;
  for (const auto& extension : extensions) {
    if (extension == "*" ||
        base::EndsWith(path.value(), "." + extension,
                       base::CompareCase::INSENSITIVE_ASCII))
      return path;
  }
  return path.ReplaceExtension(extensions[0]);
}
}  
bool ShowOpenDialog(const DialogSettings& settings,