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

Source/core/loader/appcache/ApplicationCache.h

 /*
  * Copyright (C) 2008, 2009 Apple 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 30 matching lines @@
 
 class ApplicationCache final : public RefCountedGarbageCollectedEventTargetWithInlineData<ApplicationCache>, public DOMWindowProperty {
     DEFINE_WRAPPERTYPEINFO();
     REFCOUNTED_GARBAGE_COLLECTED_EVENT_TARGET(ApplicationCache);
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(ApplicationCache);
 public:
     static ApplicationCache* create(LocalFrame* frame)
     {
         return new ApplicationCache(frame);
     }
-    virtual ~ApplicationCache()
+    ~ApplicationCache() override
     {
 #if !ENABLE(OILPAN)
         ASSERT(!m_frame);
 #endif
     }
 
-    virtual void willDestroyGlobalObjectInFrame() override;
+    void willDestroyGlobalObjectInFrame() override;
 
     unsigned short status() const;
     void update(ExceptionState&);
     void swapCache(ExceptionState&);
     void abort();
 
     // Explicitly named attribute event listener helpers
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(checking);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(error);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(noupdate);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(downloading);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(progress);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(updateready);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(cached);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(obsolete);
 
-    virtual const AtomicString& interfaceName() const override;
-    virtual ExecutionContext* executionContext() const override;
+    const AtomicString& interfaceName() const override;
+    ExecutionContext* executionContext() const override;
 
     static const AtomicString& toEventType(ApplicationCacheHost::EventID);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit ApplicationCache(LocalFrame*);
 
     ApplicationCacheHost* applicationCacheHost() const;
 };
 
 } // namespace blink
 
 #endif // ApplicationCache_h