Make ChromeVox Next a setting in options page.

chrome/browser/resources/chromeos/chromevox/cvox2/background/cursors.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 Classes related to cursors that point to and select parts of
  * the automation tree.
  */
 
 goog.provide('cursors.Cursor');
@@ skipping 296 matching lines @@
     newNode = newNode || originalNode;
     newIndex = goog.isDef(newIndex) ? newIndex : this.index_;
     return new cursors.Cursor(newNode, newIndex);
   },
 
   /**
    * Returns whether this cursor points to a valid position.
    * @return {boolean}
    */
   isValid: function() {
-    return !!this.node && !!this.node.root;
+    return this.node != null;
   }
 };
 
 /**
  * A cursors.Cursor that wraps from beginning to end and vice versa when moved.
  * @constructor
  * @param {!AutomationNode} node
  * @param {number} index A 0-based index into this cursor node's primary
  * accessible name. An index of |cursors.NODE_INDEX| means the node as a whole
  * is pointed to and covers the case where the accessible text is empty.
@@ skipping 220 matching lines @@
   select: function() {
     var start = this.start.node;
     var end = this.end.node;
 
     if (!start || !end)
       return;
 
     // Find the most common root.
     var uniqueAncestors = AutomationUtil.getUniqueAncestors(start, end);
     var mcr = start.root;
-    if (uniqueAncestors)
-      mcr = uniqueAncestors.pop().parent.root;
+    if (uniqueAncestors) {
+      var common = uniqueAncestors.pop().parent;
+      if (common)
+        mcr = common.root;
+    }
 
-    if (mcr.role == RoleType.desktop)
+    if (!mcr || mcr.role == RoleType.desktop)
       return;
 
     if (mcr === start.root && mcr === end.root) {
       start = start.role == RoleType.inlineTextBox ? start.parent : start;
       end = end.role == RoleType.inlineTextBox ? end.parent : end;
 
       if (!start || !end)
         return;
 
       chrome.automation.setDocumentSelection(
@@ skipping 18 matching lines @@
   /**
    * Returns whether this range has valid start and end cursors.
    * @return {boolean}
    */
   isValid: function() {
     return this.start.isValid() && this.end.isValid();
   }
 };
 
 });  // goog.scope