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

Source/modules/mediastream/MediaStreamRegistry.h

 /*
  * Copyright (C) 2011 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 @@
 
 class KURL;
 class MediaStreamDescriptor;
 
 class MODULES_EXPORT MediaStreamRegistry final : public URLRegistry {
 public:
     // Returns a single instance of MediaStreamRegistry.
     static MediaStreamRegistry& registry();
 
     // Registers a blob URL referring to the specified stream data.
-    virtual void registerURL(SecurityOrigin*, const KURL&, URLRegistrable*) override;
-    virtual void unregisterURL(const KURL&) override;
-    virtual bool contains(const String&) override;
+    void registerURL(SecurityOrigin*, const KURL&, URLRegistrable*) override;
+    void unregisterURL(const KURL&) override;
+    bool contains(const String&) override;
 
     MediaStreamDescriptor* lookupMediaStreamDescriptor(const String& url);
 
 private:
     MediaStreamRegistry();
     HashMap<String, RefPtr<MediaStreamDescriptor>> m_streamDescriptors;
 };
 
 } // namespace blink
 
 #endif // MediaStreamRegistry_h