Implements hook_menu_local_tasks_alter().
function node_menu_local_tasks_alter(&$data, $router_item, $root_path) {
// Add action link to 'node/add' on 'admin/content' page.
if ($root_path == 'admin/content') {
$item = menu_get_item('node/add');
if ($item['access']) {
$data['actions']['output'][] = array(
'#theme' => 'menu_local_action',
'#link' => $item,
);
}
}
}