WebUI: Stop keypresses on the close icon from firing the Enter handler.

chrome/test/data/webui/cr_elements/cr_dialog_test.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.
 
 suite('cr-dialog', function() {
   function pressEnter(element) {
     MockInteractions.keyEventOn(element, 'keypress', 13, undefined, 'Enter');
   }
 
   setup(function() {
@@ skipping 33 matching lines @@
     var actionButton = document.body.querySelector('.action-button');
 
     dialog.showModal();
 
     // MockInteractions triggers event listeners synchronously.
     var clickedCounter = 0;
     actionButton.addEventListener('click', function() {
       clickedCounter++;
     });
 
+    // Enter key on the action button should only fire the click handler once.
+    MockInteractions.tap(actionButton, 'keypress', 13, undefined, 'Enter');
+    assertEquals(1, clickedCounter);
+
     // Enter keys on other buttons should be ignored.
     clickedCounter = 0;
     var otherButton = document.body.querySelector('#other-button');
     assertTrue(!!otherButton);
     pressEnter(otherButton);
     assertEquals(0, clickedCounter);
 
-    // Enter key on the action button should only fire the click handler once.
-    MockInteractions.tap(actionButton, 'keypress', 13, undefined, 'Enter');
-    assertEquals(1, clickedCounter);
+    // Enter keys on the close icon in the top-right corner should be ignored.
+    pressEnter(dialog.getCloseButton());
+    assertEquals(0, clickedCounter);
   });
 
   test('enter keys find the first non-hidden non-disabled button', function() {
     document.body.innerHTML = `
       <dialog is="cr-dialog">
         <div class="title">title</div>
         <div class="body">
           <button id="hidden" class="action-button" hidden>hidden</button>
           <button class="action-button" disabled>disabled</button>
           <button class="action-button" disabled hidden>disabled hidden</button>
@@ skipping 136 matching lines @@
           break;
       }
     });
     observer.observe(bodyContainer, {attributes: true});
 
     // Height is normally set via CSS, but mixin doesn't work with innerHTML.
     bodyContainer.style.height = '1px';
     bodyContainer.scrollTop = 100;
   });
 });