Add close button to the supervised user pages.

chrome/browser/resources/chromeos/login/screen_supervised_user_creation.js

Index: chrome/browser/resources/chromeos/login/screen_supervised_user_creation.js
diff --git a/chrome/browser/resources/chromeos/login/screen_supervised_user_creation.js b/chrome/browser/resources/chromeos/login/screen_supervised_user_creation.js
index be8f355afb8977c9f6ee17db776ad3c0c3f183d5..e7574c8defd8cd945b93e670d7fbef7c72a81848 100644
--- a/chrome/browser/resources/chromeos/login/screen_supervised_user_creation.js
+++ b/chrome/browser/resources/chromeos/login/screen_supervised_user_creation.js
@@ -616,6 +616,17 @@ login.createScreen('SupervisedUserCreationScreen',
           'webkitTransitionEnd', function(e) {
             previewElement.classList.remove('animation');
           });
+
+      $('supervised-user-creation-close-button-item').addEventListener(
+          'mousedown', function(e) {
+            e.preventDefault();

[dzhioev (left Google), 2015/05/15 02:35:20]

This trick is not needed for "gaia-icon-button" as well

[achuithb, 2015/05/15 22:10:14]

Done.

+          });
+
+      $('supervised-user-creation-close-button-item').addEventListener(
+          'click', function(e) {
+            this.cancel();
+            e.preventDefault();
+          }.bind(this));
     },
 
     buttonIds: [],