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

Source/core/fetch/XSLStyleSheetResource.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
@@ skipping 22 matching lines @@
 
 class FetchRequest;
 class ResourceFetcher;
 
 class XSLStyleSheetResource final : public StyleSheetResource {
 public:
     static ResourcePtr<XSLStyleSheetResource> fetch(FetchRequest&, ResourceFetcher*);
 
     const String& sheet() const { return m_sheet; }
 
-    virtual void didAddClient(ResourceClient*) override;
+    void didAddClient(ResourceClient*) override;
 
 protected:
     class XSLStyleSheetResourceFactory : public ResourceFactory {
     public:
         XSLStyleSheetResourceFactory()
             : ResourceFactory(Resource::XSLStyleSheet) { }
 
         Resource* create(const ResourceRequest& request, const String& charset) const override
         {
             return new XSLStyleSheetResource(request, charset);
         }
     };
     XSLStyleSheetResource(const ResourceRequest&, const String& charset);
 
-    virtual void checkNotify() override;
+    void checkNotify() override;
 
     String m_sheet;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(XSLStyleSheet);
 
 } // namespace blink
 
 #endif