Plugin_Upgrader::bulk_upgrade

				'destination'       => WP_PLUGIN_DIR,
				'clear_destination' => true,
				'clear_working'     => true,
				'hook_extra'        => array(
					'plugin' => $plugin,
					'type'   => 'plugin',
					'action' => 'update',
				),
			)
		);

		// Cleanup our hooks, in case something else does a upgrade on this connection.
		remove_action( 'upgrader_process_complete', 'wp_clean_plugins_cache', 9 );
		remove_filter( 'upgrader_pre_install', array( $this, 'deactivate_plugin_before_upgrade' ) );
		remove_filter( 'upgrader_pre_install', array( $this, 'active_before' ) );
		remove_filter( 'upgrader_clear_destination', array( $this, 'delete_old_plugin' ) );
		remove_filter( 'upgrader_post_install', array( $this, 'active_after' ) );

		if ( ! $this->result || is_wp_error( $this->result ) ) {
			return $this->result;
		}

		// Force refresh of plugin update information.
		wp_clean_plugins_cache( $parsed_args['clear_update_cache'] );

		// Ensure any future auto-update failures trigger a failure email by removing
		// the last failure notification from the list when plugins update successfully.
		$past_failure_emails = get_option( 'auto_plugin_theme_update_emails', array() );

		if ( isset( $past_failure_emails[ $plugin ] ) ) {
			unset( $past_failure_emails[ $plugin ] );
			update_option( 'auto_plugin_theme_update_emails', $past_failure_emails );
		}

		return true;
	}

	/**
	 * Bulk upgrade several plugins at once.
	 *
	 * @since 2.8.0
	 * @since 3.7.0 The `$args` parameter was added, making clearing the plugin update cache optional.
	 *
	 * @param string[] $plugins Array of paths to plugin files relative to the plugins directory.
	 * @param array    $args {
	 *     Optional. Other arguments for upgrading several plugins at once.
	 *
	 *     @type bool $clear_update_cache Whether to clear the plugin updates cache if successful. Default true.
	 * }
	 * @return array|false An array of results indexed by plugin file, or false if unable to connect to the filesystem.
	 */
	public function bulk_upgrade( $plugins, $args = array() ) {
		$defaults    = array(
			'clear_update_cache' => true,
		);
		$parsed_args = wp_parse_args( $args, $defaults );

		$this->init();
		$this->bulk = true;
		$this->upgrade_strings();

		$current = get_site_transient( 'update_plugins' );

		add_filter( 'upgrader_clear_destination', array( $this, 'delete_old_plugin' ), 10, 4 );

		$this->skin->header();

		// Connect to the filesystem first.
		$res = $this->fs_connect( array( WP_CONTENT_DIR, WP_PLUGIN_DIR ) );
		if ( ! $res ) {
			$this->skin->footer();
			return false;
		}

		$this->skin->bulk_header();

		/*
		 * Only start maintenance mode if:
		 * - running Multisite and there are one or more plugins specified, OR
		 * - a plugin with an update available is currently active.
		 * @todo For multisite, maintenance mode should only kick in for individual sites if at all possible.
		 */
		$maintenance = ( is_multisite() && ! empty( $plugins ) );
		foreach ( $plugins as $plugin ) {
			$maintenance = $maintenance || ( is_plugin_active( $plugin ) && isset( $current->response[ $plugin ] ) );
		}
		if ( $maintenance ) {
			$this->maintenance_mode( true );
		}

		$results = array();

		$this->update_count   = count( $plugins );
		$this->update_current = 0;
		foreach ( $plugins as $plugin ) {
			$this->update_current++;
			$this->skin->plugin_info = get_plugin_data( WP_PLUGIN_DIR . '/' . $plugin, false, true );

			if ( ! isset( $current->response[ $plugin ] ) ) {
				$this->skin->set_result( 'up_to_date' );
				$this->skin->before();
				$this->skin->feedback( 'up_to_date' );
				$this->skin->after();
				$results[ $plugin ] = true;
				continue;
			}

			// Get the URL to the zip file.
			$r = $current->response[ $plugin ];