commit fc2dc71f7d1426b815b47c67564d7c41bc33af70
Author: Daniel Marlatt <marlatt@rhs.msu.edu>
Date:   Mon May 27 00:10:55 2013 -0400

    2003334-accessmodifier

diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/style/StylePluginBase.php b/core/modules/views/lib/Drupal/views/Plugin/views/style/StylePluginBase.php
index c26b661..8409c9d 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/style/StylePluginBase.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/style/StylePluginBase.php
@@ -519,7 +519,7 @@ function render_grouping_sets($sets, $level = 0) {
    *   )
    *   @endcode
    */
-  function renderGrouping($records, $groupings = array(), $group_rendered = NULL) {
+  public function renderGrouping($records, $groupings = array(), $group_rendered = NULL) {
     // This is for backward compability, when $groupings was a string containing
     // the ID of a single field.
     if (is_string($groupings)) {