Move a member function parentEditingBoundary() out from PositionAlgorithm<Strategy> template class

Source/core/editing/VisibleUnits.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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 442 matching lines @@
 }
 
 
 enum BoundarySearchContextAvailability { DontHaveMoreContext, MayHaveMoreContext };
 
 typedef unsigned (*BoundarySearchFunction)(const UChar*, unsigned length, unsigned offset, BoundarySearchContextAvailability, bool& needMoreContext);
 
 static VisiblePosition previousBoundary(const VisiblePosition& c, BoundarySearchFunction searchFunction)
 {
     Position pos = c.deepEquivalent();
-    Node* boundary = pos.parentEditingBoundary();
+    Node* boundary = parentEditingBoundary(pos);
     if (!boundary)
         return VisiblePosition();
 
     Document& d = boundary->document();
     Position start = Position::editingPositionOf(boundary, 0).parentAnchoredEquivalent();
     Position end = pos.parentAnchoredEquivalent();
 
     Vector<UChar, 1024> string;
     unsigned suffixLength = 0;
 
@@ skipping 57 matching lines @@
     // Use the character iterator to translate the next value into a DOM position.
     BackwardsCharacterIterator charIt(start, end);
     charIt.advance(string.size() - suffixLength - next);
     // FIXME: charIt can get out of shadow host.
     return VisiblePosition(charIt.endPosition());
 }
 
 static VisiblePosition nextBoundary(const VisiblePosition& c, BoundarySearchFunction searchFunction)
 {
     Position pos = c.deepEquivalent();
-    Node* boundary = pos.parentEditingBoundary();
+    Node* boundary = parentEditingBoundary(pos);
     if (!boundary)
         return VisiblePosition();
 
     Document& d = boundary->document();
     Position start(pos.parentAnchoredEquivalent());
 
     Vector<UChar, 1024> string;
     unsigned prefixLength = 0;
 
     if (requiresContextForWordBoundary(c.characterAfter())) {
@@ skipping 1044 matching lines @@
 
     if (previousRenderedEditable(position1.anchorNode()) == position2.anchorNode()
         && !renderedOffset1 && renderedOffset2 == caretMaxOffset(position2.anchorNode())) {
         return false;
     }
 
     return true;
 }
 
 }