David Roberts 697a08e742 [ML] Refactor so ML doesn't require PersistentTasksService at startup (elastic/x-pack-elasticsearch#3682)
At present the PersistentTasksService is created inside the ML plugin.
This is undesirable, as other plugins will use persistent tasks in the
near future.

This change refactors the startup code so that the PersistentTasksService
no longer needs to be passed to any constructors for ML components.

A future change will still be required to actually move the initialization
of the PersistentTasksClusterService, PersistentTasksService and
PersistentTasksExecutorRegistry out of the ML plugin, but following this
change it should be fairly simple.

Original commit: elastic/x-pack-elasticsearch@3c2a8e020e
2018-01-23 16:55:08 +00:00
..
2018-01-18 16:34:25 -08:00