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/message_box_gtk.cc
std::string lower = base::ToLowerASCII(text);
    if (lower == "cancel")
      return GTK_STOCK_CANCEL;
    else if (lower == "no")
      return GTK_STOCK_NO;
    else if (lower == "ok")
      return GTK_STOCK_OK;
    else if (lower == "yes")
      return GTK_STOCK_YES;
    else
      return text.c_str();
  }
  void Show() {
    gtk_widget_show_all(dialog_);
    
    
    int time = ui::X11EventSource::GetInstance()->GetTimestamp();
    gtk_window_present_with_time(GTK_WINDOW(dialog_), time);
  }
  int RunSynchronous() {
    Show();
    int response = gtk_dialog_run(GTK_DIALOG(dialog_));
    if (response < 0)
      return cancel_id_;
    else
      return response;
  }
  void RunAsynchronous(const MessageBoxCallback& callback) {