How to edit title on Edit post pages?

Add this code instead on your functions.php, this will change the post and product title to the post or product that is being edit:

add_filter('admin_title', 'my_admin_title', 10, 2);
function my_admin_title($admin_title, $title)
{
        global $post, $action;
        if ( isset($post->post_title) and $action == 'edit' ){
        return 'Edit < '.$post->post_title.' - '.get_bloginfo('name');
        } else {
            return $title .' - ' .get_bloginfo('name');
        }
}