Remove unused functions in wp-admin/includes/update.php

[solarissmoke]

Just noticed these two functions, wp_update_plugin() and wp_update_theme(), which aren't used anywhere in core, and haven't been for a very long time far as I can tell. Looks like redundant code.

[SergeyBiryukov]

Unused since [11005].

wp_update_plugin() is used in at least one plugin (outdated though):
​http://plugins.trac.wordpress.org/browser/ajax-plugin-helper/tags/1.0.5/ajax-plugin-helper.php#L294
And was mentioned on the forums at least once:
​http://wordpress.org/support/topic/programmatically-update-wordpress

Perhaps it's safer to deprecate them.

[dd32]

Perhaps it's safer to Deprecate them, but I think we might be able to get away with just removing them.

From what I can see, all the major things use the classes directly, and we should push people to using WP CLI or similar for custom scripts (since they handle the edgecases better)

[dd32]

In 25307:

Upgrader: Deprecate a few mostly unused functions, wp_update_plugin(), wp_update_theme(), and, wp_update_core().
wp_update_core() was still used, as it was never updated to make use of the newer Skins. Fixes #21874