WP 3.9 Shortcode button missing

Hi,

Today i’ve updated to 3.9 and shortcode button missing on post and page editor, here is my plugin code:

class SYMPLE_TinyMCE_Buttons {
	function __construct() {
    	add_action( 'init', array(&$this,'init') );
    }
    function init() {
		if ( ! current_user_can('edit_posts') && ! current_user_can('edit_pages') )
			return;
		if ( get_user_option('rich_editing') == 'true' ) {
			add_filter( 'mce_external_plugins', array(&$this, 'add_plugin') );
			add_filter( 'mce_buttons', array(&$this,'register_button') );
		}
    }
	function add_plugin($plugin_array) {
	   $plugin_array['symple_shortcodes'] = plugin_dir_url( __FILE__ ) .'js/symple_shortcodes_tinymce.js';
	   return $plugin_array;
	}
	function register_button($buttons) {
	   array_push($buttons, "symple_shortcodes_button");
	   return $buttons;
	}
}
$sympleshortcode = new SYMPLE_TinyMCE_Buttons;