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

Source/core/html/HTMLMapElement.h

Index: Source/core/html/HTMLMapElement.h
diff --git a/Source/core/html/HTMLMapElement.h b/Source/core/html/HTMLMapElement.h
index b98df180044a2377bd72d7955bf8e8fee2fddd3a..f94cd2c672548612a0d974b145b77adf64bb38d4 100644
--- a/Source/core/html/HTMLMapElement.h
+++ b/Source/core/html/HTMLMapElement.h
@@ -35,7 +35,7 @@ class CORE_EXPORT HTMLMapElement final : public HTMLElement {
     DEFINE_WRAPPERTYPEINFO();
 public:
     DECLARE_NODE_FACTORY(HTMLMapElement);
-    virtual ~HTMLMapElement();
+    ~HTMLMapElement() override;
 
     const AtomicString& getName() const { return m_name; }
 
@@ -47,10 +47,10 @@ public:
 private:
     explicit HTMLMapElement(Document&);
 
-    virtual void parseAttribute(const QualifiedName&, const AtomicString&) override;
+    void parseAttribute(const QualifiedName&, const AtomicString&) override;
 
-    virtual InsertionNotificationRequest insertedInto(ContainerNode*) override;
-    virtual void removedFrom(ContainerNode*) override;
+    InsertionNotificationRequest insertedInto(ContainerNode*) override;
+    void removedFrom(ContainerNode*) override;
 
     AtomicString m_name;
 };