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

Source/core/editing/FrameSelection.cpp

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 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 622 matching lines @@
         bool movingBackwardsMovedPositionToStartOfCurrentWord = positionAfterCurrentWord.deepEquivalent() == previousWordPosition(nextWordPosition(originalPosition)).deepEquivalent();
         if (movingBackwardsMovedPositionToStartOfCurrentWord)
             positionAfterCurrentWord = positionAfterSpacingAndFollowingWord;
     }
     return positionAfterCurrentWord;
 }
 
 static void adjustPositionForUserSelectAll(VisiblePosition& pos, bool isForward)
 {
     if (Node* rootUserSelectAll = EditingStrategy::rootUserSelectAllForNode(pos.deepEquivalent().anchorNode()))
-        pos = VisiblePosition(isForward ? positionAfterNode(rootUserSelectAll).downstream(CanCrossEditingBoundary) : positionBeforeNode(rootUserSelectAll).upstream(CanCrossEditingBoundary));
+        pos = VisiblePosition(isForward ? mostForwardCaretPosition(positionAfterNode(rootUserSelectAll), CanCrossEditingBoundary) : mostBackwardCaretPosition(positionBeforeNode(rootUserSelectAll), CanCrossEditingBoundary));
 }
 
 VisiblePosition FrameSelection::modifyExtendingRight(TextGranularity granularity)
 {
     VisiblePosition pos(m_selection.extent(), m_selection.affinity());
 
     // The difference between modifyExtendingRight and modifyExtendingForward is:
     // modifyExtendingForward always extends forward logically.
     // modifyExtendingRight behaves the same as modifyExtendingForward except for extending character or word,
     // it extends forward logically if the enclosing block is LTR direction,
@@ skipping 1404 matching lines @@
 
 void showTree(const blink::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
     else
         fprintf(stderr, "Cannot showTree for (nil) FrameSelection.\n");
 }
 
 #endif