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

Source/core/fetch/RawResource.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 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 80 matching lines @@
 }
 #endif
 inline RawResource* toRawResource(const ResourcePtr<Resource>& resource)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!resource || isRawResource(*resource.get()));
     return static_cast<RawResource*>(resource.get());
 }
 
 class CORE_EXPORT RawResourceClient : public ResourceClient {
 public:
-    virtual ~RawResourceClient() { }
+    ~RawResourceClient() override {}
     static ResourceClientType expectedType() { return RawResourceType; }
-    virtual ResourceClientType resourceClientType() const override final { return expectedType(); }
+    ResourceClientType resourceClientType() const final { return expectedType(); }
 
     virtual void dataSent(Resource*, unsigned long long /* bytesSent */, unsigned long long /* totalBytesToBeSent */) { }
     virtual void responseReceived(Resource*, const ResourceResponse&, PassOwnPtr<WebDataConsumerHandle>) { }
     virtual void setSerializedCachedMetadata(Resource*, const char*, size_t) { }
     virtual void dataReceived(Resource*, const char* /* data */, unsigned /* length */) { }
     virtual void redirectReceived(Resource*, ResourceRequest&, const ResourceResponse&) { }
     virtual void updateRequest(Resource*, const ResourceRequest&) { }
     virtual void dataDownloaded(Resource*, int) { }
     virtual void didReceiveResourceTiming(Resource*, const ResourceTimingInfo&) { }
 };
 
 }
 
 #endif // RawResource_h