Track all changed nodes during an update

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.
 
 // TODO(nektar): Migrate entire file to Mojoq.
 // 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
@@ skipping 486 matching lines @@
   };
 
   enum AXDescriptionFrom {
     uninitialized,
     attribute,
     contents,
     placeholder,
     related_element
   };
 
+  enum AXEventFrom {
+    user,
+    page,
+    action
+  };
+
   // Touch gestures on Chrome OS.
   enum AXGesture {
     click,
     swipe_left_1,
     swipe_up_1,
     swipe_right_1,
     swipe_down_1,
     swipe_left_2,
     swipe_up_2,
     swipe_right_2,
@@ skipping 21 matching lines @@
     // First node is before the second one.
     before,
 
     // Nodes are the same.
     equal,
 
     // First node is after the second one.
     after
   };
 };