[CodeHealth] Use Position::anchorNode instead of deprecatedNode.

Source/core/editing/iterators/SimplifiedBackwardsTextIterator.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov.
  *
  * 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
@@ skipping 64 matching lines @@
     , m_textLength(0)
     , m_singleCharacterBuffer(0)
     , m_havePassedStartNode(false)
     , m_shouldHandleFirstLetter(false)
     , m_stopsOnFormControls(behavior & TextIteratorStopsOnFormControls)
     , m_shouldStop(false)
     , m_emitsOriginalText(false)
 {
     ASSERT(behavior == TextIteratorDefaultBehavior || behavior == TextIteratorStopsOnFormControls);
 
-    Node* startNode = start.deprecatedNode();
+    Node* startNode = start.anchorNode();
     if (!startNode)
         return;
-    Node* endNode = end.deprecatedNode();
+    Node* endNode = end.anchorNode();
     int startOffset = start.deprecatedEditingOffset();
     int endOffset = end.deprecatedEditingOffset();
 
     init(startNode, endNode, startOffset, endOffset);
 }
 
 template <typename Strategy>
 void SimplifiedBackwardsTextIteratorAlgorithm<Strategy>::init(Node* startNode, Node* endNode, int startOffset, int endOffset)
 {
     if (!startNode->offsetInCharacters() && startOffset >= 0) {
@@ skipping 279 matching lines @@
     if (m_positionNode)
         return PositionAlgorithm<Strategy>::createLegacyEditingPosition(m_positionNode, m_positionEndOffset);
     return PositionAlgorithm<Strategy>::createLegacyEditingPosition(m_startNode, m_startOffset);
 }
 
 template class CORE_TEMPLATE_EXPORT SimplifiedBackwardsTextIteratorAlgorithm<EditingStrategy>;
 template class CORE_TEMPLATE_EXPORT SimplifiedBackwardsTextIteratorAlgorithm<EditingInComposedTreeStrategy>;
 
 
 } // namespace blink