Add custom action support

ui/accessibility/ax_tree.cc

 // Copyright 2013 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.
 
 #include "ui/accessibility/ax_tree.h"
 
 #include <stddef.h>
 
 #include <set>
 
@@ skipping 389 matching lines @@
   auto intlist_callback = [this, node](
                               AXIntListAttribute attr,
                               const std::vector<int32_t>& old_intlist,
                               const std::vector<int32_t>& new_intlist) {
     delegate_->OnIntListAttributeChanged(this, node, attr, old_intlist,
                                          new_intlist);
   };
   CallIfAttributeValuesChanged(old_data.intlist_attributes,
                                new_data.intlist_attributes,
                                std::vector<int32_t>(), intlist_callback);
+
+  // TODO(yawano): Add StringListAttribute
 }
 
 void AXTree::DestroySubtree(AXNode* node,
                             AXTreeUpdateState* update_state) {
   DCHECK(update_state);
   if (delegate_) {
     if (!update_state->HasChangedNode(node))
       delegate_->OnSubtreeWillBeDeleted(this, node);
     else
       delegate_->OnSubtreeWillBeReparented(this, node);
@@ skipping 73 matching lines @@
       update_state->pending_nodes.insert(child);
       update_state->new_nodes.insert(child);
     }
     new_children->push_back(child);
   }
 
   return success;
 }
 
 }  // namespace ui