Range: node offsets should be unsigned.

third_party/WebKit/Source/core/dom/NodeWithIndex.h

 /*
  * Copyright (C) 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 23 matching lines @@
 // For use when you want to get the index for a node repeatedly and
 // only want to walk the child list to figure out the index once.
 class NodeWithIndex {
   STACK_ALLOCATED();
 
  public:
   explicit NodeWithIndex(Node& node) : m_node(node), m_index(-1) {}
 
   Node& node() const { return *m_node; }
 
+  // TODO(tkent): Should be unsigned.
   int index() const {
     if (!hasIndex())
       m_index = node().nodeIndex();
     DCHECK(hasIndex());
     DCHECK_EQ(m_index, static_cast<int>(node().nodeIndex()));
     return m_index;
   }
 
  private:
   bool hasIndex() const { return m_index >= 0; }
 
   Member<Node> m_node;
   mutable int m_index;
 };
 
 }  // namespace blink
 
 #endif