Fix virtual/override/final usage in Source/core/dom/.

Source/core/dom/StaticNodeList.h

 /*
  * Copyright (C) 2007, 2008 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
@@ skipping 32 matching lines @@
 template <typename NodeType>
 class StaticNodeTypeList final : public NodeList {
 public:
     static PassRefPtrWillBeRawPtr<StaticNodeTypeList> adopt(WillBeHeapVector<RefPtrWillBeMember<NodeType>>& nodes);
 
     static PassRefPtrWillBeRawPtr<StaticNodeTypeList> createEmpty()
     {
         return adoptRefWillBeNoop(new StaticNodeTypeList);
     }
 
-    virtual ~StaticNodeTypeList();
+    ~StaticNodeTypeList() override;
 
-    virtual unsigned length() const override;
-    virtual NodeType* item(unsigned index) const override;
+    unsigned length() const override;
+    NodeType* item(unsigned index) const override;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     ptrdiff_t AllocationSize()
     {
         return m_nodes.capacity() * sizeof(RefPtrWillBeMember<NodeType>);
     }
 
     WillBeHeapVector<RefPtrWillBeMember<NodeType>> m_nodes;
@@ skipping 40 matching lines @@
 template <typename VisitorDispatcher>
 ALWAYS_INLINE void StaticNodeTypeList<NodeType>::traceImpl(VisitorDispatcher visitor)
 {
     visitor->trace(m_nodes);
     NodeList::trace(visitor);
 }
 
 } // namespace blink
 
 #endif // StaticNodeList_h