Fix virtual/override/final usage in Source/core/{fetch,loader,streams,xmlhttprequest}/.

Source/core/streams/Stream.h

 /*
  * Copyright (C) 2013 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 35 matching lines @@
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Stream);
     DEFINE_WRAPPERTYPEINFO();
 public:
     static Stream* create(ExecutionContext* context, const String& mediaType)
     {
         Stream* stream = new Stream(context, mediaType);
         stream->suspendIfNeeded();
         return stream;
     }
 
-    virtual ~Stream();
+    ~Stream() override;
 
     // Returns the internal URL referring to this stream.
     const KURL& url() const { return m_internalURL; }
     // Returns the media type of this stream.
     const String& type() const { return m_mediaType; }
 
     // Appends data to this stream.
     void addData(const char* data, size_t len);
     // Flushes contents buffered in the stream.
     void flush();
     // Mark this stream finalized so that a reader of this stream is notified
     // of EOF.
     void finalize();
     // Mark this stream finalized due to an error so that a reader of this
     // stream is notified of EOF due to the error.
     void abort();
 
     // Allow an external reader class to mark this object neutered so that they
     // won't load the corresponding stream again. All stream objects are
     // read-once for now.
     void neuter() { m_isNeutered = true; }
     bool isNeutered() const { return m_isNeutered; }
 
     // Implementation of ActiveDOMObject.
     //
     // FIXME: Implement suspend() and resume() when necessary.
-    virtual void suspend() override;
-    virtual void resume() override;
-    virtual void stop() override;
+    void suspend() override;
+    void resume() override;
+    void stop() override;
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     Stream(ExecutionContext*, const String& mediaType);
 
     // This is an internal URL referring to the blob data associated with this object. It serves
     // as an identifier for this blob. The internal URL is never used to source the blob's content
     // into an HTML or for FileRead'ing, public blob URLs must be used for those purposes.
     KURL m_internalURL;
 
     String m_mediaType;
 
     bool m_isNeutered;
 };
 
 } // namespace blink
 
 #endif // Stream_h