Language settings: fix focus issues

chrome/browser/resources/settings/languages_page/add_languages_dialog.js

Index: chrome/browser/resources/settings/languages_page/add_languages_dialog.js
diff --git a/chrome/browser/resources/settings/languages_page/add_languages_dialog.js b/chrome/browser/resources/settings/languages_page/add_languages_dialog.js
index 43457ca2e1fc70b736c2fdaaf1e4733845e9be1e..4d682c57b3fbb68b144921bd25b1a4af93e46da9 100644
--- a/chrome/browser/resources/settings/languages_page/add_languages_dialog.js
+++ b/chrome/browser/resources/settings/languages_page/add_languages_dialog.js
@@ -34,10 +34,24 @@ Polymer({
 
   attached: function() {
     this.$.dialog.showModal();
-    // Fire iron-resize after the list initially displays to prevent flickering.
-    setTimeout(function() {
-      this.$$('iron-list').fire('iron-resize');
-    }.bind(this));
+    // To prevent flashing the Cancel button focus, "focus" the disabled Add
+    // button, so nothing has a focus state until the afterShown_ call.
+    this.$$('.action-button').focus();

[stevenjb, 2016/11/28 17:49:16]

This seems klugey. Can we just blur the cancel button instead?

[michaelpg, 2016/12/01 23:19:13]

Done. Thought I had tried that!

+    setTimeout(this.afterShown_.bind(this));
+  },
+
+  /**
+   * Re-initializes the dialog after it is shown.
+   * @private
+   */
+  afterShown_: function() {
+    // Only fire iron-list after the list displayed to prevent flickering.

[stevenjb, 2016/11/28 17:49:16]

'fire iron-resize' ?

[michaelpg, 2016/12/01 23:19:13]

Done.

+    this.$$('iron-list').fire('iron-resize');
+
+    // Focus the top checkbox, assuming there are languages left to enable.
+    var firstCheckbox = this.$$('iron-list paper-checkbox');
+    if (firstCheckbox)
+      firstCheckbox.focus();
   },
 
   /**