[feature/extension-manager] Remove cron's dependency on the extension manager.

Instead a separate cron provider supplies the manager with tasks from the
extension finder.

PHPBB3-10323

phpBB/includes/cron/manager.php

@@ -32,65 +32,25 @@ class phpbb_cron_manager
 	*/
 	protected $tasks = array();
 
-	/**
-	* An extension manager to search for cron tasks in extensions.
-	* @var phpbb_extension_manager
-	*/
-	protected $extension_manager;
-
 	/**
 	* Constructor. Loads all available tasks.
 	*
-	* Tasks will be looked up in the core task directory located in
-	* includes/cron/task/core/ and in extensions. Task classes will be
-	* autoloaded and must be named according to autoloading naming conventions.
-	*
-	* Tasks in extensions must be located in a directory called cron or a subdir
-	* of a directory called cron. The class and filename must end in a _task
-	* suffix.
-	*
-	* @param phpbb_extension_manager $extension_manager phpBB extension manager
+	* @param array|Traversable $task_names Provides an iterable set of task names
 	*/
-	public function __construct(phpbb_extension_manager $extension_manager)
+	public function __construct($task_names)
 	{
-		$this->extension_manager = $extension_manager;
-
-		$task_names = $this->find_cron_task_names();
 		$this->load_tasks($task_names);
 	}
 
-	/**
-	* Finds cron task names using the extension manager.
-	*
-	* All PHP files in includes/cron/task/core/ are considered tasks. Tasks
-	* in extensions have to be located in a directory called cron or a subdir
-	* of a directory called cron. The class and filename must end in a _task
-	* suffix.
-	*
-	* @return array		List of task names
-	*/
-	public function find_cron_task_names()
-	{
-		$finder = $this->extension_manager->get_finder();
-
-		return $finder
-			->suffix('_task')
-			->directory('/cron')
-			->default_path('includes/cron/task/core/')
-			->default_suffix('')
-			->default_directory('')
-			->get_classes();
-	}
-
 	/**
 	* Loads tasks given by name, wraps them
 	* and puts them into $this->tasks.
 	*
-	* @param array $task_names		Array of strings
+	* @param array|Traversable $task_names		Array of strings
 	*
 	* @return void
 	*/
-	public function load_tasks(array $task_names)
+	public function load_tasks($task_names)
 	{
 		foreach ($task_names as $task_name)
 		{