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

Source/core/dom/FirstLetterPseudoElement.h

Index: Source/core/dom/FirstLetterPseudoElement.h
diff --git a/Source/core/dom/FirstLetterPseudoElement.h b/Source/core/dom/FirstLetterPseudoElement.h
index 4528fcf8b2e4bb06f676b4cd9ee87778f1867e4a..1eaff1574345e44f81d324c46cad266b678971ac 100644
--- a/Source/core/dom/FirstLetterPseudoElement.h
+++ b/Source/core/dom/FirstLetterPseudoElement.h
@@ -42,7 +42,7 @@ public:
         return adoptRefWillBeNoop(new FirstLetterPseudoElement(parent));
     }
 
-    virtual ~FirstLetterPseudoElement();
+    ~FirstLetterPseudoElement() override;
 
     static LayoutObject* firstLetterTextLayoutObject(const Element&);
     static unsigned firstLetterLength(const String&);
@@ -52,13 +52,13 @@ public:
 
     void updateTextFragments();
 
-    virtual void attach(const AttachContext& = AttachContext()) override;
-    virtual void detach(const AttachContext& = AttachContext()) override;
+    void attach(const AttachContext& = AttachContext()) override;
+    void detach(const AttachContext& = AttachContext()) override;
 
 private:
     explicit FirstLetterPseudoElement(Element*);
 
-    virtual void didRecalcStyle(StyleRecalcChange) override;
+    void didRecalcStyle(StyleRecalcChange) override;
 
     void attachFirstLetterTextLayoutObjects();
     ComputedStyle* styleForFirstLetter(LayoutObject*);