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

Source/core/fetch/ScriptResource.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 19 matching lines @@
 #include "core/fetch/ResourceClient.h"
 #include "core/fetch/TextResource.h"
 
 namespace blink {
 
 class FetchRequest;
 class ScriptResource;
 
 class CORE_EXPORT ScriptResourceClient : public ResourceClient {
 public:
-    virtual ~ScriptResourceClient() { }
+    ~ScriptResourceClient() override {}
     static ResourceClientType expectedType() { return ScriptType; }
-    virtual ResourceClientType resourceClientType() const override final { return expectedType(); }
+    ResourceClientType resourceClientType() const final { return expectedType(); }
 
     virtual void notifyAppendData(ScriptResource* resource) { }
 };
 
 class CORE_EXPORT ScriptResource final : public TextResource {
 public:
     typedef ScriptResourceClient ClientType;
     static ResourcePtr<ScriptResource> fetch(FetchRequest&, ResourceFetcher*);
 
     // Public for testing
     ScriptResource(const ResourceRequest&, const String& charset);
 
-    virtual ~ScriptResource();
+    ~ScriptResource() override;
 
-    virtual void didAddClient(ResourceClient*) override;
-    virtual void appendData(const char*, unsigned) override;
+    void didAddClient(ResourceClient*) override;
+    void appendData(const char*, unsigned) override;
 
     const String& script();
 
     AtomicString mimeType() const;
 
     bool mimeTypeAllowedByNosniff() const;
 
 private:
     class ScriptResourceFactory : public ResourceFactory {
     public:
         ScriptResourceFactory()
             : ResourceFactory(Resource::Script) { }
 
         Resource* create(const ResourceRequest& request, const String& charset) const override
         {
             return new ScriptResource(request, charset);
         }
     };
 
     AtomicString m_script;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(Script);
 
 }
 
 #endif