MDL-29360 quiz comment.php has broken JS for the Cancel button.

This swtichest it to more modern YUI3 approach.

mod/quiz/comment.php

@@ -74,14 +74,15 @@
                 <div class="fgrouplabel"><label> </label></div>
             </div>
             <fieldset class="felement fgroup">
-                <input id="id_submitbutton" type="submit" name="submit" value="<?php print_string('save', 'quiz'); ?>"/>
-                <input id="id_cancel" type="button" value="<?php print_string('cancel'); ?>" onclick="close_window"/>
+                <input id="id_submitbutton" type="submit" name="submit" value="<?php
+                        print_string('save', 'quiz'); ?>"/>
             </fieldset>
         </div>
     </div>
 </fieldset>
 <?php
     echo '</form>';
+    $PAGE->requires->js_init_call('M.mod_quiz.init_comment_popup', null, false, quiz_get_js_module());
 
 /// End of the page.
     echo $OUTPUT->footer();

mod/quiz/locallib.php

@@ -1239,11 +1239,13 @@ function quiz_check_safe_browser() {
 
 function quiz_get_js_module() {
     global $PAGE;
+
     return array(
         'name' => 'mod_quiz',
         'fullpath' => '/mod/quiz/module.js',
         'requires' => array('base', 'dom', 'event-delegate', 'event-key', 'core_question_engine'),
         'strings' => array(
+            array('cancel', 'moodle'),
             array('timesup', 'quiz'),
             array('functiondisabledbysecuremode', 'quiz'),
             array('flagged', 'question'),

mod/quiz/module.js

@@ -16,6 +16,14 @@ M.mod_quiz.init_review_form = function(Y) {
     Y.on('submit', function(e) { e.halt(); }, '.questionflagsaveform');
 };
 
+M.mod_quiz.init_comment_popup = function(Y) {
+    // Add a close button to the window.
+    var closebutton = Y.Node.create('<input type="button" />');
+    closebutton.set('value', M.util.get_string('cancel', 'moodle'));
+    Y.one('#id_submitbutton').ancestor().append(closebutton);
+    Y.on('click', function() { window.close() }, closebutton);
+}
+
 // Code for updating the countdown timer that is used on timed quizzes.
 M.mod_quiz.timer = {
     // YUI object.