Move Node/ContainerNode's traverseToChildAt() to NodeTraversal

Source/core/editing/BreakBlockquoteCommand.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 100 matching lines @@
 
     // Split at pos if in the middle of a text node.
     if (startNode->isTextNode()) {
         Text* textNode = toText(startNode);
         if ((unsigned)pos.deprecatedEditingOffset() >= textNode->length()) {
             startNode = NodeTraversal::next(*startNode);
             ASSERT(startNode);
         } else if (pos.deprecatedEditingOffset() > 0)
             splitTextNode(textNode, pos.deprecatedEditingOffset());
     } else if (pos.deprecatedEditingOffset() > 0) {
-        Node* childAtOffset = startNode->traverseToChildAt(pos.deprecatedEditingOffset());
+        Node* childAtOffset = NodeTraversal::childAt(*startNode, pos.deprecatedEditingOffset());
         startNode = childAtOffset ? childAtOffset : NodeTraversal::next(*startNode);
         ASSERT(startNode);
     }
 
     // If there's nothing inside topBlockquote to move, we're finished.
     if (!startNode->isDescendantOf(topBlockquote)) {
         setEndingSelection(VisibleSelection(VisiblePosition(firstPositionInOrBeforeNode(startNode)), endingSelection().isDirectional()));
         return;
     }
 
@@ skipping 50 matching lines @@
 
     // Make sure the cloned block quote renders.
     addBlockPlaceholderIfNeeded(clonedBlockquote.get());
 
     // Put the selection right before the break.
     setEndingSelection(VisibleSelection(positionBeforeNode(breakElement.get()), DOWNSTREAM, endingSelection().isDirectional()));
     rebalanceWhitespace();
 }
 
 } // namespace blink