Fix virtual/override/final usage in Source/core/editing/.

Source/core/editing/SplitTextNodeContainingElementCommand.h

 /*
  * Copyright (C) 2005, 2006, 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 24 matching lines @@
     static PassRefPtrWillBeRawPtr<SplitTextNodeContainingElementCommand> create(PassRefPtrWillBeRawPtr<Text> node, int offset)
     {
         return adoptRefWillBeNoop(new SplitTextNodeContainingElementCommand(node, offset));
     }
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     SplitTextNodeContainingElementCommand(PassRefPtrWillBeRawPtr<Text>, int offset);
 
-    virtual void doApply() override;
+    void doApply() override;
 
     RefPtrWillBeMember<Text> m_text;
     int m_offset;
 };
 
 } // namespace blink
 
 #endif // SplitTextNodeContainingElementCommand_h