Update more core classes to use OVERRIDE / FINAL when needed

Source/core/fileapi/FileReaderLoader.h

 /*
  * Copyright (C) 2010 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 45 matching lines @@
         ReadAsArrayBuffer,
         ReadAsBinaryString,
         ReadAsBlob,
         ReadAsText,
         ReadAsDataURL,
         ReadByClient
     };
 
     // If client is given, do the loading asynchronously. Otherwise, load synchronously.
     FileReaderLoader(ReadType, FileReaderLoaderClient*);
-    ~FileReaderLoader();
+    virtual ~FileReaderLoader();
 
     void start(ExecutionContext*, PassRefPtr<BlobDataHandle>);
     void start(ExecutionContext*, const Stream&, unsigned readSize);
     void cancel();
 
     // ThreadableLoaderClient
     virtual void didReceiveResponse(unsigned long, const ResourceResponse&) OVERRIDE;
     virtual void didReceiveData(const char*, int) OVERRIDE;
     virtual void didFinishLoading(unsigned long, double) OVERRIDE;
     virtual void didFail(const ResourceError&) OVERRIDE;
@@ skipping 61 matching lines @@
     bool m_hasRange;
     unsigned m_rangeStart;
     unsigned m_rangeEnd;
 
     FileError::ErrorCode m_errorCode;
 };
 
 } // namespace WebCore
 
 #endif // FileReaderLoader_h