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

ui/webui/resources/cr_elements/cr_dialog/cr_dialog.js

Index: ui/webui/resources/cr_elements/cr_dialog/cr_dialog.js
diff --git a/ui/webui/resources/cr_elements/cr_dialog/cr_dialog.js b/ui/webui/resources/cr_elements/cr_dialog/cr_dialog.js
index d15ed9b8173a769d12afe886806d1509a99cfffc..bc9421c8e96dbec4fbae2c6ba4306cde6efd8ff7 100644
--- a/ui/webui/resources/cr_elements/cr_dialog/cr_dialog.js
+++ b/ui/webui/resources/cr_elements/cr_dialog/cr_dialog.js
@@ -41,6 +41,12 @@ Polymer({
     }.bind(this));
   },
 
+  attached: function() {

[Dan Beam, 2017/02/23 06:22:24]

i also considered overriding showModal() but liked this slightly better

[dpapad, 2017/02/23 18:28:35]

Nit: Add @override

Also that looks fine. If/when we address
https://bugs.chromium.org/p/chromium/issues/detail?id=668313, we  will plobably
have to add our own show() method (similar to the cr-action-menu's showAt()), so
we could move this in that method.

[Dan Beam, 2017/02/24 05:43:09]

Done.

+    var title = this.getContentChildren('[select=".title"]');
+    if (title.length)
+      title[0].tabIndex = -1;
+  },
+
   cancel: function() {
     this.fire('cancel');
     HTMLDialogElement.prototype.close.call(this, '');