Remove getNodesInCommand debug method from Editing commands

Source/core/editing/AppendNodeCommand.cpp

 /*
  * 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 41 matching lines @@
 }
 
 void AppendNodeCommand::doUnapply()
 {
     if (!m_parent->rendererIsEditable())
         return;
 
     m_node->remove(IGNORE_EXCEPTION);
 }
 
-#ifndef NDEBUG
-void AppendNodeCommand::getNodesInCommand(HashSet<Node*>& nodes)
-{
-    addNodeAndDescendants(m_parent.get(), nodes);
-    addNodeAndDescendants(m_node.get(), nodes);
-}
-#endif
-
 } // namespace WebCore