Ignore unknown focusable nodes if they have children

chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_predicate.js

 // Copyright 2014 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 ChromeVox predicates for the automation extension API.
  */
 
 goog.provide('AutomationPredicate');
 goog.provide('AutomationPredicate.Binary');
@@ skipping 295 matching lines @@
  * @return {boolean}
  */
 AutomationPredicate.structuralContainer = AutomationPredicate.roles([
     Role.ALERT_DIALOG,
     Role.DIALOG,
     Role.ROOT_WEB_AREA,
     Role.WEB_VIEW,
     Role.WINDOW,
     Role.EMBEDDED_OBJECT,
     Role.IFRAME,
-    Role.IFRAME_PRESENTATIONAL]);
+    Role.IFRAME_PRESENTATIONAL,
+    Role.UNKNOWN]);
 
 /**
  * Returns whether the given node should not be crossed when performing
  * traversals up the ancestry chain.
  * @param {AutomationNode} node
  * @return {boolean}
  */
 AutomationPredicate.root = function(node) {
   switch (node.role) {
     case Role.WINDOW:
@@ skipping 163 matching lines @@
  * Matches against nodes that we may be able to retrieve image data from.
  * @param {!AutomationNode} node
  * @return {boolean}
  */
 AutomationPredicate.supportsImageData = AutomationPredicate.roles([
     Role.CANVAS,
     Role.IMAGE,
     Role.VIDEO]);
 
 });  // goog.scope