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

Source/core/xmlhttprequest/XMLHttpRequestProgressEventThrottle.h

 /*
  * Copyright (C) 2010 Julien Chaffraix <jchaffraix@webkit.org>
  * All right 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
@@ skipping 37 matching lines @@
 // In the comments for this class:
 // - "progress" event means an event named "progress"
 // - ProgressEvent means an event using the ProgressEvent interface defined in
 //   the spec.
 class XMLHttpRequestProgressEventThrottle final : public NoBaseWillBeGarbageCollectedFinalized<XMLHttpRequestProgressEventThrottle>, public TimerBase {
 public:
     static PassOwnPtrWillBeRawPtr<XMLHttpRequestProgressEventThrottle> create(XMLHttpRequest* eventTarget)
     {
         return adoptPtrWillBeNoop(new XMLHttpRequestProgressEventThrottle(eventTarget));
     }
-    virtual ~XMLHttpRequestProgressEventThrottle();
+    ~XMLHttpRequestProgressEventThrottle() override;
 
     enum DeferredEventAction {
         Ignore,
         Clear,
         Flush,
     };
 
     // Dispatches a ProgressEvent.
     //
     // Special treatment for events named "progress" is implemented to dispatch
@@ skipping 16 matching lines @@
 
 private:
     explicit XMLHttpRequestProgressEventThrottle(XMLHttpRequest*);
 
     // The main purpose of this class is to throttle the "progress"
     // ProgressEvent dispatching. This class represents such a deferred
     // "progress" ProgressEvent.
     class DeferredEvent;
     static const double minimumProgressEventDispatchingIntervalInSeconds;
 
-    virtual void fired() override;
+    void fired() override;
     void dispatchDeferredEvent();
 
     // Non-Oilpan, keep a weak pointer to our XMLHttpRequest object as it is
     // the one holding us. With Oilpan, a simple strong Member can be used -
     // this XMLHttpRequestProgressEventThrottle (part) object dies together
     // with the XMLHttpRequest object.
     RawPtrWillBeMember<XMLHttpRequest> m_target;
 
     // A slot for the deferred "progress" ProgressEvent. When multiple events
     // arrive, only the last one is stored and others are discarded.
     const OwnPtr<DeferredEvent> m_deferred;
 };
 
 } // namespace blink
 
 #endif // XMLHttpRequestProgressEventThrottle_h