Index: wp-admin/includes/class-wp-upgrader.php
===================================================================
--- wp-admin/includes/class-wp-upgrader.php	(revision 28074)
+++ wp-admin/includes/class-wp-upgrader.php	(working copy)
@@ -347,6 +347,7 @@
 		);
 
 		$options = wp_parse_args($options, $defaults);
+		$options = apply_filters( 'upgrader_package_options', $options );
 		extract($options);
 
 		if ( ! $is_multi ) // call $this->header separately if running multiple times