Make VisiblePosition constructor private

Source/core/dom/Range.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Gunnstein Lye (gunnstein@netcom.no)
  * (C) 2000 Frederik Holljen (frederik.holljen@hig.no)
  * (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1561 matching lines @@
     ASSERT(oldNode.parentNode());
     ASSERT(oldNode.nextSibling());
     ASSERT(oldNode.nextSibling()->isTextNode());
     boundaryTextNodeSplit(m_start, oldNode);
     boundaryTextNodeSplit(m_end, oldNode);
     ASSERT(boundaryPointsValid());
 }
 
 void Range::expand(const String& unit, ExceptionState& exceptionState)
 {
-    VisiblePosition start(startPosition());
-    VisiblePosition end(endPosition());
+    VisiblePosition start = createVisiblePosition(startPosition());
+    VisiblePosition end = createVisiblePosition(endPosition());
     if (unit == "word") {
         start = startOfWord(start);
         end = endOfWord(end);
     } else if (unit == "sentence") {
         start = startOfSentence(start);
         end = endOfSentence(end);
     } else if (unit == "block") {
         start = startOfParagraph(start);
         end = endOfParagraph(end);
     } else if (unit == "document") {
@@ skipping 88 matching lines @@
 {
     if (range && range->boundaryPointsValid()) {
         range->startContainer()->showTreeAndMark(range->startContainer(), "S", range->endContainer(), "E");
         fprintf(stderr, "start offset: %d, end offset: %d\n", range->startOffset(), range->endOffset());
     } else {
         fprintf(stderr, "Cannot show tree if range is null, or if boundary points are invalid.\n");
     }
 }
 
 #endif