Remove getNodesInCommand debug method from Editing commands

Source/core/editing/ReplaceNodeWithSpanCommand.h

 /*
  * Copyright (c) 2009 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 35 matching lines @@
     }
 
     HTMLElement* spanElement() { return m_spanElement.get(); }
 
 private:
     explicit ReplaceNodeWithSpanCommand(PassRefPtr<HTMLElement>);
 
     virtual void doApply() OVERRIDE;
     virtual void doUnapply() OVERRIDE;
 
-#ifndef NDEBUG
-    virtual void getNodesInCommand(HashSet<Node*>&) OVERRIDE;
-#endif
-
     RefPtr<HTMLElement> m_elementToReplace;
     RefPtr<HTMLElement> m_spanElement;
 };
 
 } // namespace WebCore
 
 #endif // ReplaceNodeWithSpanCommand