Fix virtual/override/final usage in Source/modules/.

Source/modules/filesystem/DirectoryReaderSync.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 34 matching lines @@
 typedef HeapVector<Member<EntrySync>> EntrySyncHeapVector;
 
 class DirectoryReaderSync : public DirectoryReaderBase, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static DirectoryReaderSync* create(DOMFileSystemBase* fileSystem, const String& fullPath)
     {
         return new DirectoryReaderSync(fileSystem, fullPath);
     }
 
-    virtual ~DirectoryReaderSync();
+    ~DirectoryReaderSync() override;
 
     EntrySyncHeapVector readEntries(ExceptionState&);
 
     void addEntries(const EntrySyncHeapVector& entries)
     {
         m_entries.appendVector(entries);
     }
 
     void setError(FileError::ErrorCode code)
     {
         m_errorCode = code;
     }
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     class EntriesCallbackHelper;
     class ErrorCallbackHelper;
 
     DirectoryReaderSync(DOMFileSystemBase*, const String& fullPath);
 
     int m_callbacksId;
     EntrySyncHeapVector m_entries;
     FileError::ErrorCode m_errorCode;
 };
 
 } // namespace blink
 
 #endif // DirectoryReaderSync_h