Issue #2020695 by heddn: Rename Views method summary_join() to summaryJoin().

core/modules/views/lib/Drupal/views/ManyToOneHelper.php

@@ -119,7 +119,7 @@ public function getJoin() {
    * Provide the proper join for summary queries. This is important in part because
    * it will cooperate with other arguments if possible.
    */
-  function summary_join() {
+  public function summaryJoin() {
     $field = $this->handler->relationship . '_' . $this->handler->table . '.' . $this->handler->field;
     $join = $this->getJoin();
 

core/modules/views/lib/Drupal/views/Plugin/views/argument/ManyToOne.php

@@ -173,7 +173,7 @@ protected function summaryQuery() {
       $this->tableAlias = $this->query->ensureTable($this->table, $this->relationship, $join);
     }
     else {
-      $this->tableAlias = $this->helper->summary_join();
+      $this->tableAlias = $this->helper->summaryJoin();
     }
 
     // Add the field.

core/modules/views/lib/Drupal/views/Plugin/views/argument/String.php

@@ -151,7 +151,7 @@ protected function summaryQuery() {
       $this->ensureMyTable();
     }
     else {
-      $this->tableAlias = $this->helper->summary_join();
+      $this->tableAlias = $this->helper->summaryJoin();
     }
 
     if (empty($this->options['glossary'])) {