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

Source/core/html/shadow/MediaControls.h

Index: Source/core/html/shadow/MediaControls.h
diff --git a/Source/core/html/shadow/MediaControls.h b/Source/core/html/shadow/MediaControls.h
index b35d6211a2bd11578c60f2f1f82997304b228e4f..0c8f7ad3b959a3755d7dca5e027373463508189b 100644
--- a/Source/core/html/shadow/MediaControls.h
+++ b/Source/core/html/shadow/MediaControls.h
@@ -104,9 +104,9 @@ private:
     void tryShowOverlayCastButton();
 
     // Node
-    virtual bool isMediaControls() const override { return true; }
-    virtual bool willRespondToMouseMoveEvents() override { return true; }
-    virtual void defaultEventHandler(Event*) override;
+    bool isMediaControls() const override { return true; }
+    bool willRespondToMouseMoveEvents() override { return true; }
+    void defaultEventHandler(Event*) override;
     bool containsRelatedTarget(Event*);
 
     RawPtrWillBeMember<HTMLMediaElement> m_mediaElement;