MD User Manager: Refactors existing dialogs in User Manager into <user-manager-dialog>

chrome/test/data/webui/md_user_manager/control_bar_tests.js

Index: chrome/test/data/webui/md_user_manager/control_bar_tests.js
diff --git a/chrome/test/data/webui/md_user_manager/control_bar_tests.js b/chrome/test/data/webui/md_user_manager/control_bar_tests.js
index 30ac5a43b73bc1054519f0db70a0c4f2eddcd2ff..956c806d4cc890d991e535231871c483e15bc603 100644
--- a/chrome/test/data/webui/md_user_manager/control_bar_tests.js
+++ b/chrome/test/data/webui/md_user_manager/control_bar_tests.js
@@ -95,7 +95,7 @@ cr.define('user_manager.control_bar_tests', function() {
           Polymer.dom.flush();
 
           // The dialog is visible.
-          assertLT(0, errorDialogElement.$$('#backdrop').offsetHeight);
+          assertTrue(errorDialogElement.$.dialog.opened);
         });
       });
 
@@ -108,7 +108,7 @@ cr.define('user_manager.control_bar_tests', function() {
           Polymer.dom.flush();
 
           // The error dialog is visible.
-          assertLT(0, errorDialogElement.$$('#backdrop').offsetHeight);
+          assertTrue(errorDialogElement.$.dialog.opened);
         });
       });
     });