MD WebUI: Use arrow keys for navigation in cr-shared-menu, close on tab

chrome/test/data/webui/cr_elements/cr_shared_menu_tests.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** @fileoverview Suite of tests for cr-shared-menu. */
 suite('cr-shared-menu', function() {
   var menu;
 
   var button;
   var button2;
 
   var item1;
   var item2;
   var item3;
 
   function afterOpen(callback) {
     menu.addEventListener('iron-overlay-opened', function f() {
       menu.removeEventListener('iron-overlay-opened', f);
-      callback();
+      // paper-listbox applies focus after opening with microtask timing.
+      // Delay until that has happened:
+      setTimeout(callback, 0);
     });
   }
 
   function afterClose(callback) {
     menu.addEventListener('iron-overlay-closed', function f() {
       menu.removeEventListener('iron-overlay-closed', f);
       callback();
     });
   }
 
@@ skipping 109 matching lines @@
       input.focus();
       menu.closeMenu();
 
       afterClose(function() {
         assertEquals(input, document.activeElement);
         done();
       });
     });
   });
 
-  test('focus is trapped inside the menu', function(done) {
+  test('tab closes menu', function(done) {
     button.focus();
     MockInteractions.tap(button);
 
     afterOpen(function() {
-      // Simulate shift-tab on first element.
-      assertEquals(item1, menu.shadowRoot.activeElement);
-      MockInteractions.pressAndReleaseKeyOn(item1, 9, ['shift']);
-      assertEquals(item3, menu.shadowRoot.activeElement);
+      MockInteractions.pressAndReleaseKeyOn(item1, 9);
+      afterClose(function() {
+        done();
+      });
+    });
+  });
 
-      // Simulate tab on last element.
-      MockInteractions.pressAndReleaseKeyOn(item3, 9);
-      assertEquals(item1, menu.shadowRoot.activeElement);
+  test('up and down change focus', function(done) {
+    button.focus();
+    MockInteractions.tap(button);
 
+    afterOpen(function() {
+      assertEquals(item1, document.activeElement);
+      MockInteractions.pressAndReleaseKeyOn(item1, 40);
+
+      assertEquals(item2, document.activeElement);
+      MockInteractions.pressAndReleaseKeyOn(item2, 38);
       done();
     });
   });
 });