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

Source/web/UserMediaClientImpl.h

Index: Source/web/UserMediaClientImpl.h
diff --git a/Source/web/UserMediaClientImpl.h b/Source/web/UserMediaClientImpl.h
index 591d0ac8df007763e99ea67d11544c2e52e5c38b..ff18aefd7408b71d51892189751487d58cb5f6e0 100644
--- a/Source/web/UserMediaClientImpl.h
+++ b/Source/web/UserMediaClientImpl.h
@@ -46,11 +46,11 @@ public:
     explicit UserMediaClientImpl(WebLocalFrameImpl*);
 
     // UserMediaClient ----------------------------------------------
-    virtual void requestUserMedia(UserMediaRequest*) override;
-    virtual void cancelUserMediaRequest(UserMediaRequest*) override;
-    virtual void requestMediaDevices(MediaDevicesRequest*) override;
-    virtual void cancelMediaDevicesRequest(MediaDevicesRequest*) override;
-    virtual void requestSources(MediaStreamTrackSourcesRequest*) override;
+    void requestUserMedia(UserMediaRequest*) override;
+    void cancelUserMediaRequest(UserMediaRequest*) override;
+    void requestMediaDevices(MediaDevicesRequest*) override;
+    void cancelMediaDevicesRequest(MediaDevicesRequest*) override;
+    void requestSources(MediaStreamTrackSourcesRequest*) override;
 
 private:
     UserMediaClientImpl();