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

Source/core/fetch/ResourceLoader.h

 /*
  * Copyright (C) 2005, 2006, 2011 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
@@ skipping 30 matching lines @@
 
 class Resource;
 class KURL;
 class ResourceError;
 class ResourceFetcher;
 class ThreadedDataReceiver;
 
 class CORE_EXPORT ResourceLoader final : public GarbageCollectedFinalized<ResourceLoader>, protected WebURLLoaderClient {
 public:
     static ResourceLoader* create(ResourceFetcher*, Resource*, const ResourceRequest&, const ResourceLoaderOptions&);
-    virtual ~ResourceLoader();
+    ~ResourceLoader() override;
     DECLARE_TRACE();
 
     void start();
     void changeToSynchronous();
 
     void cancel();
     void cancel(const ResourceError&);
     void cancelIfNotFinishing();
 
     Resource* cachedResource() { return m_resource; }
@@ skipping 73 matching lines @@
     ResourceLoaderState m_state;
 
     // Used for sanity checking to make sure we don't experience illegal state
     // transitions.
     ConnectionState m_connectionState;
 };
 
 }
 
 #endif