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

Source/core/dom/DocumentType.h

Index: Source/core/dom/DocumentType.h
diff --git a/Source/core/dom/DocumentType.h b/Source/core/dom/DocumentType.h
index acff6b15d807a53b58e44c2a7bc300d109adacf4..86549b2e7ffb2314076c1f1b894cb17d676dca24 100644
--- a/Source/core/dom/DocumentType.h
+++ b/Source/core/dom/DocumentType.h
@@ -43,13 +43,13 @@ public:
 private:
     DocumentType(Document*, const String& name, const String& publicId, const String& systemId);
 
-    virtual KURL baseURI() const override;
-    virtual String nodeName() const override;
-    virtual NodeType nodeType() const override;
-    virtual PassRefPtrWillBeRawPtr<Node> cloneNode(bool deep) override;
+    KURL baseURI() const override;
+    String nodeName() const override;
+    NodeType nodeType() const override;
+    PassRefPtrWillBeRawPtr<Node> cloneNode(bool deep) override;
 
-    virtual InsertionNotificationRequest insertedInto(ContainerNode*) override;
-    virtual void removedFrom(ContainerNode*) override;
+    InsertionNotificationRequest insertedInto(ContainerNode*) override;
+    void removedFrom(ContainerNode*) override;
 
     String m_name;
     String m_publicId;