Fix virtual/override/final usage in the rest of Source/core/.

Source/core/events/GenericEventQueue.h

Index: Source/core/events/GenericEventQueue.h
diff --git a/Source/core/events/GenericEventQueue.h b/Source/core/events/GenericEventQueue.h
index e8cfef7f0d7afcf96d9ce9f7790ac7543f10f0ab..18d8c6663abb01b7308636d481406157b9c5697f 100644
--- a/Source/core/events/GenericEventQueue.h
+++ b/Source/core/events/GenericEventQueue.h
@@ -40,13 +40,13 @@ class CORE_EXPORT GenericEventQueue final : public EventQueue {
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(GenericEventQueue);
 public:
     static PassOwnPtrWillBeRawPtr<GenericEventQueue> create(EventTarget*);
-    virtual ~GenericEventQueue();
+    ~GenericEventQueue() override;
 
     // EventQueue
     DECLARE_VIRTUAL_TRACE();
-    virtual bool enqueueEvent(PassRefPtrWillBeRawPtr<Event>) override;
-    virtual bool cancelEvent(Event*) override;
-    virtual void close() override;
+    bool enqueueEvent(PassRefPtrWillBeRawPtr<Event>) override;
+    bool cancelEvent(Event*) override;
+    void close() override;
 
     void cancelAllEvents();
     bool hasPendingEvents() const;