Are the *_upgrade_grades functions actually used somewhere

Grepping through the 2.5 / 2.6 Moodle code, I see that these functions exist:

mod/assignment/lib.php:3003:function assignment_upgrade_grades() {
mod/data/lib.php:1071:function data_upgrade_grades() {
mod/forum/lib.php:858:function forum_upgrade_grades() {
mod/glossary/lib.php:777:function glossary_upgrade_grades() {
mod/lesson/lib.php:417:function lesson_upgrade_grades() {
mod/quiz/lib.php:636:function quiz_upgrade_grades() {
mod/scorm/lib.php:626:function scorm_upgrade_grades() {

 But I can't find anyplace that these are called, even from some dynamically composed code.  Perhaps my grepping skills are not strong enough ...

Does anyone know if these are just no-longer-necessary leftovers from the upgrade to Moodle 2, or are they still used?