Plugin_Upgrader::deactivate_plugin_before_upgrade( bool|WP_Error $return, array $plugin )

	public function deactivate_plugin_before_upgrade($return, $plugin) {

		if ( is_wp_error($return) ) //Bypass.
			return $return;

		// When in cron (background updates) don't deactivate the plugin, as we require a browser to reactivate it
		if ( wp_doing_cron() )
			return $return;

		$plugin = isset($plugin['plugin']) ? $plugin['plugin'] : '';
		if ( empty($plugin) )
			return new WP_Error('bad_request', $this->strings['bad_request']);

		if ( is_plugin_active($plugin) ) {
			//Deactivate the plugin silently, Prevent deactivation hooks from running.
			deactivate_plugins($plugin, true);
		}

		return $return;
	}