Move Node::lastDescendantOrSelf() to NodeTraversal and rename to lastWithinOrSelf()

Source/core/editing/DeleteSelectionCommand.cpp

 /*
  * Copyright (C) 2005 Apple Computer, 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 504 matching lines @@
                 // NodeTraversal::nextSkippingChildren just blew past the end position, so stop deleting
                 node = nullptr;
             } else if (!m_downstreamEnd.deprecatedNode()->isDescendantOf(node.get())) {
                 RefPtrWillBeRawPtr<Node> nextNode = NodeTraversal::nextSkippingChildren(*node);
                 // if we just removed a node from the end container, update end position so the
                 // check above will work
                 updatePositionForNodeRemoval(m_downstreamEnd, *node);
                 removeNode(node.get());
                 node = nextNode.get();
             } else {
-                Node& n = node->lastDescendantOrSelf();
+                Node& n = NodeTraversal::lastWithinOrSelf(*node);
                 if (m_downstreamEnd.deprecatedNode() == n && m_downstreamEnd.deprecatedEditingOffset() >= caretMaxOffset(&n)) {
                     removeNode(node.get());
                     node = nullptr;
                 } else {
                     node = NodeTraversal::next(*node);
                 }
             }
         }
 
         if (m_downstreamEnd.deprecatedNode() != startNode && !m_upstreamStart.deprecatedNode()->isDescendantOf(m_downstreamEnd.deprecatedNode()) && m_downstreamEnd.inDocument() && m_downstreamEnd.deprecatedEditingOffset() >= caretMinOffset(m_downstreamEnd.deprecatedNode())) {
@@ skipping 350 matching lines @@
     visitor->trace(m_deleteIntoBlockquoteStyle);
     visitor->trace(m_startRoot);
     visitor->trace(m_endRoot);
     visitor->trace(m_startTableRow);
     visitor->trace(m_endTableRow);
     visitor->trace(m_temporaryPlaceholder);
     CompositeEditCommand::trace(visitor);
 }
 
 } // namespace blink