MD Settings: focus header when dialog shows to signal to AT what's going on

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

Index: chrome/test/data/webui/cr_elements/cr_dialog_test.js
diff --git a/chrome/test/data/webui/cr_elements/cr_dialog_test.js b/chrome/test/data/webui/cr_elements/cr_dialog_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..fa617c543d471d8521e8107352035dd3501bd0a0
--- /dev/null
+++ b/chrome/test/data/webui/cr_elements/cr_dialog_test.js
@@ -0,0 +1,41 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.

[dpapad, 2017/02/24 20:46:10]

Nit: 2017

[Dan Beam, 2017/02/24 22:08:31]

Acknowledged.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+suite('cr-dialog', function() {
+  setup(function() {
+    PolymerTest.clearBody();
+  });
+
+  test('focuses title on show', function() {
+    document.body.innerHTML = `
+      <dialog is="cr-dialog">
+        <div class="title">title</div>
+        <div class="body"><button>button</button></div>
+      </dialog>`;
+
+    assertFalse(document.activeElement.matches('div.title'));
+    assertFalse(document.activeElement.matches('button'));
+
+    document.body.querySelector('dialog').showModal();
+
+    expectTrue(document.activeElement.matches('div.title'));

[dpapad, 2017/02/24 20:46:10]

I am not asking you to replace expects with asserts, but can we be at least
consistent within the same tests, to use either asserts or expects but not both?

[Dan Beam, 2017/02/24 22:08:31]

they're different.

+    expectFalse(document.activeElement.matches('button'));
+  });
+
+  test('focuses [autofocus] instead of title when present', function() {
+    document.body.innerHTML = `
+      <dialog is="cr-dialog">
+        <div class="title">title</div>
+        <div class="body"><button autofocus>button</button></div>
+      </dialog>`;
+
+    assertFalse(document.activeElement.matches('button'));
+    assertFalse(document.activeElement.matches('div.title'));
+
+    document.body.querySelector('dialog').showModal();
+
+    expectTrue(document.activeElement.matches('button'));
+    expectFalse(document.activeElement.matches('div.title'));
+  });
+});