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

Source/core/dom/Comment.h

Index: Source/core/dom/Comment.h
diff --git a/Source/core/dom/Comment.h b/Source/core/dom/Comment.h
index 97c56c9572a5bd331f1edfd0afc029679ae5cba9..bdc5ebee5611f325e674605c823d4529f7137f7a 100644
--- a/Source/core/dom/Comment.h
+++ b/Source/core/dom/Comment.h
@@ -35,9 +35,9 @@ public:
 private:
     Comment(Document&, const String&);
 
-    virtual String nodeName() const override;
-    virtual NodeType nodeType() const override;
-    virtual PassRefPtrWillBeRawPtr<Node> cloneNode(bool deep = true) override;
+    String nodeName() const override;
+    NodeType nodeType() const override;
+    PassRefPtrWillBeRawPtr<Node> cloneNode(bool deep = true) override;
 };
 
 DEFINE_NODE_TYPE_CASTS(Comment, nodeType() == Node::COMMENT_NODE);