Implement 3 Mac accessibility parameterized attributes

ui/accessibility/ax_enums.idl

 // 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.
 
 // These should be kept in sync with third_party/WebKit/public/web/WebAXEnums.h
 // until the Chromium and Blink trees are merged.
 [camel_case_enum_to_string=true] namespace ui {
 
   // For new entries to the following three enums, also add to
   // chrome/common/extensions/api/automation.idl.
@@ skipping 495 matching lines @@
     swipe_left_4,
     swipe_up_4,
     swipe_right_4,
     swipe_down_4
   };
 
   enum AXTextAffinity {
     downstream = 0,
     upstream = 1
   };
+
+  // Compares two nodes in an accessibility tree in pre-order traversal.
+  enum AXTreeOrder {
+    undefined,  // Not in the same tree, or other error.
+    before,     // First node is before the second one.
+    equal,      // Nodes are the same.
+    after       // First node is after the second one.
+  };
 };