diff -r c7c34916027a -r 177826044cd9 wp/wp-admin/includes/class-bulk-theme-upgrader-skin.php
--- a/wp/wp-admin/includes/class-bulk-theme-upgrader-skin.php	Mon Oct 14 18:06:33 2019 +0200
+++ b/wp/wp-admin/includes/class-bulk-theme-upgrader-skin.php	Mon Oct 14 18:28:13 2019 +0200
@@ -16,27 +16,26 @@
  * @see Bulk_Upgrader_Skin
  */
 class Bulk_Theme_Upgrader_Skin extends Bulk_Upgrader_Skin {
-	public $theme_info = array(); // Theme_Upgrader::bulk() will fill this in.
+	public $theme_info = array(); // Theme_Upgrader::bulk_upgrade() will fill this in.
 
 	public function add_strings() {
 		parent::add_strings();
-		$this->upgrader->strings['skin_before_update_header'] = __('Updating Theme %1$s (%2$d/%3$d)');
+		/* translators: 1: name of theme being updated, 2: number of updating themes, 3: total number of themes being updated */
+		$this->upgrader->strings['skin_before_update_header'] = __( 'Updating Theme %1$s (%2$d/%3$d)' );
 	}
 
 	/**
-	 *
 	 * @param string $title
 	 */
-	public function before($title = '') {
-		parent::before( $this->theme_info->display('Name') );
+	public function before( $title = '' ) {
+		parent::before( $this->theme_info->display( 'Name' ) );
 	}
 
 	/**
-	 *
 	 * @param string $title
 	 */
-	public function after($title = '') {
-		parent::after( $this->theme_info->display('Name') );
+	public function after( $title = '' ) {
+		parent::after( $this->theme_info->display( 'Name' ) );
 		$this->decrement_update_count( 'theme' );
 	}
 
@@ -44,24 +43,26 @@
 	 */
 	public function bulk_footer() {
 		parent::bulk_footer();
-		$update_actions =  array(
-			'themes_page' => '<a href="' . self_admin_url( 'themes.php' ) . '" target="_parent">' . __( 'Return to Themes page' ) . '</a>',
-			'updates_page' => '<a href="' . self_admin_url( 'update-core.php' ) . '" target="_parent">' . __( 'Return to WordPress Updates page' ) . '</a>'
+		$update_actions = array(
+			'themes_page'  => '<a href="' . self_admin_url( 'themes.php' ) . '" target="_parent">' . __( 'Return to Themes page' ) . '</a>',
+			'updates_page' => '<a href="' . self_admin_url( 'update-core.php' ) . '" target="_parent">' . __( 'Return to WordPress Updates page' ) . '</a>',
 		);
-		if ( ! current_user_can( 'switch_themes' ) && ! current_user_can( 'edit_theme_options' ) )
+		if ( ! current_user_can( 'switch_themes' ) && ! current_user_can( 'edit_theme_options' ) ) {
 			unset( $update_actions['themes_page'] );
+		}
 
 		/**
 		 * Filters the list of action links available following bulk theme updates.
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param array $update_actions Array of theme action links.
-		 * @param array $theme_info     Array of information for the last-updated theme.
+		 * @param string[] $update_actions Array of theme action links.
+		 * @param WP_Theme $theme_info     Theme object for the last-updated theme.
 		 */
 		$update_actions = apply_filters( 'update_bulk_theme_complete_actions', $update_actions, $this->theme_info );
 
-		if ( ! empty($update_actions) )
-			$this->feedback(implode(' | ', (array)$update_actions));
+		if ( ! empty( $update_actions ) ) {
+			$this->feedback( implode( ' | ', (array) $update_actions ) );
+		}
 	}
 }