Index: src/wp-includes/class-walker-comment.php
===================================================================
--- src/wp-includes/class-walker-comment.php	(revision 34986)
+++ src/wp-includes/class-walker-comment.php	(working copy)
@@ -130,6 +130,15 @@
 		$id_field = $this->db_fields['id'];
 		$id = $element->$id_field;
 
+		if ( isset( $element->comment_ID ) ) {
+			/**
+			 * Fires after each comment.
+			 *
+			 * @since 4.4.0
+			 */
+			do_action( 'after_comment' );
+		}
+
 		parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
 
 		// If we're at the max depth, and the current element still has children, loop over those and display them at this level