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

Source/core/events/PromiseRejectionEvent.h

Index: Source/core/events/PromiseRejectionEvent.h
diff --git a/Source/core/events/PromiseRejectionEvent.h b/Source/core/events/PromiseRejectionEvent.h
index 2468bacdc9552ba4e31bc6e336425dd9edb107a1..c905ef6e7a25bff2f1c882d9517e97c083528731 100644
--- a/Source/core/events/PromiseRejectionEvent.h
+++ b/Source/core/events/PromiseRejectionEvent.h
@@ -33,11 +33,11 @@ public:
 
     void setWrapperReference(v8::Isolate*, const v8::Persistent<v8::Object>&);
 
-    virtual const AtomicString& interfaceName() const override;
+    const AtomicString& interfaceName() const override;
 
     // PromiseRejectionEvents are similar to ErrorEvents in that they can't be
     // observed across different worlds.
-    virtual bool canBeDispatchedInWorld(const DOMWrapperWorld&) const override;
+    bool canBeDispatchedInWorld(const DOMWrapperWorld&) const override;
 
     DECLARE_VIRTUAL_TRACE();