Get rid of redundant member function PositionAlgorithm<Strategy>::{upstream,downstream}

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 1482 matching lines @@
     }
     return 0;
 }
 
 template <typename Strategy>
 PositionAlgorithm<Strategy> downstreamIgnoringEditingBoundaries(PositionAlgorithm<Strategy> position)
 {
     PositionAlgorithm<Strategy> lastPosition;
     while (position != lastPosition) {
         lastPosition = position;
-        position = position.downstream(CanCrossEditingBoundary);
+        position = mostForwardCaretPosition(position, CanCrossEditingBoundary);
     }
     return position;
 }
 
 template <typename Strategy>
 PositionAlgorithm<Strategy> upstreamIgnoringEditingBoundaries(PositionAlgorithm<Strategy> position)
 {
     PositionAlgorithm<Strategy> lastPosition;
     while (position != lastPosition) {
         lastPosition = position;
-        position = position.upstream(CanCrossEditingBoundary);
+        position = mostBackwardCaretPosition(position, CanCrossEditingBoundary);
     }
     return position;
 }
 
 template <typename Strategy>
 static InlineBoxPosition computeInlineBoxPositionAlgorithm(const PositionAlgorithm<Strategy>& position, TextAffinity affinity, TextDirection primaryDirection)
 {
     InlineBox* inlineBox = nullptr;
     int caretOffset = position.computeEditingOffset();
     Node* const anchorNode = position.anchorNode();
@@ skipping 718 matching lines @@
 // following is true:
 // 1. It is the first position in the node and the next visually equivalent
 //    position is non editable.
 // 2. It is the last position in the node and the previous visually equivalent
 //    position is non editable.
 // 3. It is an editable position and both the next and previous visually
 //    equivalent positions are both non editable.
 template <typename Strategy>
 static bool atEditingBoundary(const PositionAlgorithm<Strategy> positions)
 {
-    PositionAlgorithm<Strategy> nextPosition = positions.downstream(CanCrossEditingBoundary);
+    PositionAlgorithm<Strategy> nextPosition = mostForwardCaretPosition(positions, CanCrossEditingBoundary);
     if (positions.atFirstEditingPositionForNode() && nextPosition.isNotNull() && !nextPosition.anchorNode()->hasEditableStyle())
         return true;
 
-    PositionAlgorithm<Strategy> prevPosition = positions.upstream(CanCrossEditingBoundary);
+    PositionAlgorithm<Strategy> prevPosition = mostBackwardCaretPosition(positions, CanCrossEditingBoundary);
     if (positions.atLastEditingPositionForNode() && prevPosition.isNotNull() && !prevPosition.anchorNode()->hasEditableStyle())
         return true;
 
     return nextPosition.isNotNull() && !nextPosition.anchorNode()->hasEditableStyle()
         && prevPosition.isNotNull() && !prevPosition.anchorNode()->hasEditableStyle();
 }
 
 template <typename Strategy>
 static bool isVisuallyEquivalentCandidateAlgorithm(const PositionAlgorithm<Strategy>& position)
 {
@@ skipping 52 matching lines @@
 {
     return isVisuallyEquivalentCandidateAlgorithm<EditingStrategy>(position);
 }
 
 bool isVisuallyEquivalentCandidate(const PositionInComposedTree& position)
 {
     return isVisuallyEquivalentCandidateAlgorithm<EditingInComposedTreeStrategy>(position);
 }
 
 } // namespace blink