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

Source/modules/filesystem/SyncCallbackHelper.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2013 Samsung Electronics. 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.
@@ skipping 111 matching lines @@
         Persistent<HelperType> m_helper;
     };
 
     class ErrorCallbackImpl final : public ErrorCallback {
     public:
         static ErrorCallbackImpl* create(HelperType* helper)
         {
             return new ErrorCallbackImpl(helper);
         }
 
-        virtual void handleEvent(FileError* error) override
+        void handleEvent(FileError* error) override
         {
             ASSERT(error);
             m_helper->setError(error->code());
         }
 
     private:
         explicit ErrorCallbackImpl(HelperType* helper)
             : m_helper(helper)
         {
         }
@@ skipping 27 matching lines @@
 };
 
 typedef SyncCallbackHelper<EntryCallback, Entry*, EntrySync> EntrySyncCallbackHelper;
 typedef SyncCallbackHelper<MetadataCallback, Metadata*, Metadata> MetadataSyncCallbackHelper;
 typedef SyncCallbackHelper<VoidCallback, EmptyType*, EmptyType> VoidSyncCallbackHelper;
 typedef SyncCallbackHelper<FileSystemCallback, DOMFileSystem*, DOMFileSystemSync> FileSystemSyncCallbackHelper;
 
 } // namespace blink
 
 #endif // SyncCallbackHelper_h