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

Source/core/events/ErrorEvent.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 40 matching lines @@
         return adoptRefWillBeNoop(new ErrorEvent(message, fileName, lineNumber, columnNumber, world));
     }
     static PassRefPtrWillBeRawPtr<ErrorEvent> create(const AtomicString& type, const ErrorEventInit& initializer)
     {
         return adoptRefWillBeNoop(new ErrorEvent(type, initializer));
     }
     static PassRefPtrWillBeRawPtr<ErrorEvent> createSanitizedError(DOMWrapperWorld* world)
     {
         return adoptRefWillBeNoop(new ErrorEvent("Script error.", String(), 0, 0, world));
     }
-    virtual ~ErrorEvent();
+    ~ErrorEvent() override;
 
     // As 'message' is exposed to JavaScript, never return unsanitizedMessage.
     const String& message() const { return m_sanitizedMessage; }
     const String& filename() const { return m_fileName; }
     unsigned lineno() const { return m_lineNumber; }
     unsigned colno() const { return m_columnNumber; }
     ScriptValue error(ScriptState*) const;
 
     // 'messageForConsole' is not exposed to JavaScript, and prefers 'm_unsanitizedMessage'.
     const String& messageForConsole() const { return !m_unsanitizedMessage.isEmpty() ? m_unsanitizedMessage : m_sanitizedMessage; }
 
-    virtual const AtomicString& interfaceName() const override;
+    const AtomicString& interfaceName() const override;
 
     DOMWrapperWorld* world() const { return m_world.get(); }
 
     void setUnsanitizedMessage(const String&);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     ErrorEvent();
     ErrorEvent(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber, DOMWrapperWorld*);
     ErrorEvent(const AtomicString&, const ErrorEventInit&);
 
     String m_unsanitizedMessage;
     String m_sanitizedMessage;
     String m_fileName;
     unsigned m_lineNumber;
     unsigned m_columnNumber;
     ScriptValue m_error;
 
     RefPtr<DOMWrapperWorld> m_world;
 };
 
 } // namespace blink
 
 #endif // ErrorEvent_h