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

Source/modules/mediastream/RTCStatsRequestImpl.h

 /*
  * Copyright (C) 2012 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 24 matching lines @@
 namespace blink {
 
 class MediaStreamTrack;
 class RTCPeerConnection;
 class RTCStatsCallback;
 
 class RTCStatsRequestImpl final : public RTCStatsRequest, public ActiveDOMObject {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(RTCStatsRequestImpl);
 public:
     static RTCStatsRequestImpl* create(ExecutionContext*, RTCPeerConnection*, RTCStatsCallback*, MediaStreamTrack*);
-    virtual ~RTCStatsRequestImpl();
+    ~RTCStatsRequestImpl() override;
 
-    virtual RTCStatsResponseBase* createResponse() override;
-    virtual bool hasSelector() override;
-    virtual MediaStreamComponent* component() override;
+    RTCStatsResponseBase* createResponse() override;
+    bool hasSelector() override;
+    MediaStreamComponent* component() override;
 
-    virtual void requestSucceeded(RTCStatsResponseBase*) override;
+    void requestSucceeded(RTCStatsResponseBase*) override;
 
     // ActiveDOMObject
-    virtual void stop() override;
+    void stop() override;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     RTCStatsRequestImpl(ExecutionContext*, RTCPeerConnection*, RTCStatsCallback*, MediaStreamTrack*);
 
     void clear();
 
     Member<RTCStatsCallback> m_successCallback;
     RefPtr<MediaStreamComponent> m_component;
     Member<RTCPeerConnection> m_requester;
 };
 
 } // namespace blink
 
 #endif // RTCStatsRequestImpl_h