Introduce {next,previous}PositionOf() as replacement of {next,previous}() member functions in Positi

Source/core/editing/commands/TypingCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2007, 2008 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 457 matching lines @@
             setEndingSelection(VisibleSelection(positionBeforeNode(table), endingSelection().start(), TextAffinity::Downstream, endingSelection().isDirectional()));
             typingAddedToOpenCommand(DeleteKey);
             return;
         }
 
         selectionToDelete = selection->selection();
 
         if (granularity == CharacterGranularity && selectionToDelete.end().computeContainerNode() == selectionToDelete.start().computeContainerNode()
             && selectionToDelete.end().computeOffsetInContainerNode() - selectionToDelete.start().computeOffsetInContainerNode() > 1) {
             // If there are multiple Unicode code points to be deleted, adjust the range to match platform conventions.
-            selectionToDelete.setWithoutValidation(selectionToDelete.end(), selectionToDelete.end().previous(BackwardDeletion));
+            selectionToDelete.setWithoutValidation(selectionToDelete.end(), previousPositionOf(selectionToDelete.end(), PositionMoveType::BackwardDeletion));
         }
 
         if (!startingSelection().isRange() || selectionToDelete.base() != startingSelection().start()) {
             selectionAfterUndo = selectionToDelete;
         } else {
             // It's a little tricky to compute what the starting selection would have been in the original document.
             // We can't let the VisibleSelection class's validation kick in or it'll adjust for us based on
             // the current state of the document and we'll get the wrong result.
             selectionAfterUndo.setWithoutValidation(startingSelection().end(), selectionToDelete.extent());
         }
@@ skipping 137 matching lines @@
     ASSERT_NOT_REACHED();
     m_preservesTypingStyle = false;
 }
 
 bool TypingCommand::isTypingCommand() const
 {
     return true;
 }
 
 } // namespace blink