Fix virtual/override/final usage in Source/modules/.

Source/modules/mediastream/MediaDevicesRequest.h

 /*
  * Copyright (C) 2014 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 27 matching lines @@
 class Document;
 class ExceptionState;
 class UserMediaController;
 class ScriptState;
 class ScriptPromiseResolver;
 
 class MODULES_EXPORT MediaDevicesRequest final : public GarbageCollectedFinalized<MediaDevicesRequest>, public ActiveDOMObject {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MediaDevicesRequest);
 public:
     static MediaDevicesRequest* create(ScriptState*, UserMediaController*);
-    virtual ~MediaDevicesRequest();
+    ~MediaDevicesRequest() override;
 
     Document* ownerDocument();
 
     ScriptPromise start();
 
     void succeed(const MediaDeviceInfoVector&);
 
     // ActiveDOMObject
-    virtual void stop() override;
+    void stop() override;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     MediaDevicesRequest(ScriptState*, UserMediaController*);
 
     RawPtrWillBeMember<UserMediaController> m_controller;
     RefPtrWillBeMember<ScriptPromiseResolver> m_resolver;
 };
 
 } // namespace blink
 
 #endif // MediaDevicesRequest_h