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

Source/core/fetch/StyleSheetResourceClient.h

 /*
  Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
  Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
  Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  Copyright (C) 2011 Google 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 17 matching lines @@
 
 #include "core/fetch/ResourceClient.h"
 #include "platform/weborigin/KURL.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 class CSSStyleSheetResource;
 
 class StyleSheetResourceClient : public ResourceClient {
 public:
-    virtual ~StyleSheetResourceClient() { }
+    ~StyleSheetResourceClient() override {}
     static ResourceClientType expectedType() { return StyleSheetType; }
-    virtual ResourceClientType resourceClientType() const override final { return expectedType(); }
-    virtual void setCSSStyleSheet(const String& /* href */, const KURL& /* baseURL */, const String& /* charset */, const CSSStyleSheetResource*) { }
-    virtual void setXSLStyleSheet(const String& /* href */, const KURL& /* baseURL */, const String& /* sheet */) { }
+    ResourceClientType resourceClientType() const final { return expectedType(); }
+    virtual void setCSSStyleSheet(const String& /* href */, const KURL& /* baseURL */, const String& /* charset */, const CSSStyleSheetResource*) {}
+    virtual void setXSLStyleSheet(const String& /* href */, const KURL& /* baseURL */, const String& /* sheet */) {}
 };
 
 }
 
 #endif // StyleSheetResourceClient_h