MD Settings: Restore message shown when no "zoom" exceptions exist.

chrome/test/data/webui/settings/zoom_levels_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 zoom-levels. */
 cr.define('zoom_levels', function() {
   function registerTests() {
     suite('ZoomLevels', function() {
       /**
        * A zoom levels category created before each test.
@@ skipping 57 matching lines @@
        *     fetch.
        */
       function getRemoveButton(listContainer, index) {
         return listContainer.children[index].querySelector('paper-icon-button');
       }
 
       test('empty zoom state', function() {
         var list = testElement.$.list;
         assertTrue(!!list);
         assertEquals(0, list.items.length);
+        assertEquals(
+            0, testElement.shadowRoot.querySelectorAll('.list-item').length);
+        assertTrue(!!testElement.$$('#empty'));
       });
 
       test('non-empty zoom state', function() {
         browserProxy.setZoomList(zoomList);
 
         return initPage().then(function() {
           var list = testElement.$.list;
           assertTrue(!!list);
           assertEquals(2, list.items.length);
+          assertFalse(!!testElement.$$('#empty'));
+          assertEquals(
+              2, testElement.shadowRoot.querySelectorAll('.list-item').length);
 
           var removeButton =
               getRemoveButton(testElement.$.listContainer, 0);
           assert(!!removeButton);
           MockInteractions.tap(removeButton);
           return browserProxy.whenCalled('removeZoomLevel');
         }).then(function(args) {
           assertEquals("http://www.google.com", args[0]);
         });
       });
     });
   }
 
   return {
     registerTests: registerTests,
   };
 });