Implement the inert attribute

third_party/WebKit/Source/modules/accessibility/AXMenuListOption.cpp

 /*
  * Copyright (C) 2010 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 46 matching lines @@
   AccessibilityRole role = AriaRoleToWebCoreRole(aria_role);
   if (role)
     return role;
   return kMenuListOptionRole;
 }
 
 Element* AXMenuListOption::ActionElement() const {
   return element_;
 }
 
+AXObjectImpl* AXMenuListOption::ComputeParent() const {
+  Node* node = GetNode();
+  if (!node)
+    return nullptr;
+  HTMLSelectElement* select = toHTMLOptionElement(node)->OwnerSelectElement();
+  if (!select)
+    return nullptr;
+  AXObjectImpl* select_ax_object = AxObjectCache().GetOrCreate(select);
+  if (select_ax_object->HasChildren()) {
+    const auto& child_objects = select_ax_object->Children();
+    DCHECK(!child_objects.IsEmpty());
+    DCHECK_EQ(child_objects.size(), 1UL);
+    DCHECK(child_objects[0]->IsMenuListPopup());
+    ToAXMenuListPopup(child_objects[0].Get())->UpdateChildrenIfNecessary();
+  } else {
+    select_ax_object->UpdateChildrenIfNecessary();
+  }
+  return parent_.Get();
+}
+
 bool AXMenuListOption::IsEnabled() const {
   // isDisabledFormControl() returns true if the parent <select> element is
   // disabled, which we don't want.
   return element_ && !element_->OwnElementDisabled();
 }
 
 bool AXMenuListOption::IsVisible() const {
   if (!parent_)
     return false;
 
@@ skipping 107 matching lines @@
 
   return 0;
 }
 
 DEFINE_TRACE(AXMenuListOption) {
   visitor->Trace(element_);
   AXMockObject::Trace(visitor);
 }
 
 }  // namespace blink