Introduce enum class TextAffinity as replacement of enum EAffinity

Source/core/editing/EditingUtilities.h

 /*
  * Copyright (C) 2004, 2006, 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 182 matching lines @@
 // FIXME: isRichlyEditablePosition should also take EUpdateStyle.
 bool isEditablePosition(const Position&, EditableType = ContentIsEditable, EUpdateStyle = UpdateStyle);
 bool isEditablePosition(const PositionInComposedTree&, EditableType = ContentIsEditable, EUpdateStyle = UpdateStyle);
 bool isRichlyEditablePosition(const Position&, EditableType = ContentIsEditable);
 bool lineBreakExistsAtPosition(const Position&);
 bool isAtUnsplittableElement(const Position&);
 
 // miscellaneous functions on Position
 
 enum WhitespacePositionOption { NotConsiderNonCollapsibleWhitespace, ConsiderNonCollapsibleWhitespace };
-Position leadingWhitespacePosition(const Position&, EAffinity, WhitespacePositionOption = NotConsiderNonCollapsibleWhitespace);
-Position trailingWhitespacePosition(const Position&, EAffinity, WhitespacePositionOption = NotConsiderNonCollapsibleWhitespace);
+Position leadingWhitespacePosition(const Position&, TextAffinity, WhitespacePositionOption = NotConsiderNonCollapsibleWhitespace);
+Position trailingWhitespacePosition(const Position&, TextAffinity, WhitespacePositionOption = NotConsiderNonCollapsibleWhitespace);
 unsigned numEnclosingMailBlockquotes(const Position&);
 void updatePositionForNodeRemoval(Position&, Node&);
 
 // -------------------------------------------------------------------------
 // VisiblePosition
 // -------------------------------------------------------------------------
 
 // Functions returning VisiblePosition
 
 VisiblePosition firstEditableVisiblePositionAfterPositionInRoot(const Position&, ContainerNode*);
@@ skipping 71 matching lines @@
     // FIXME: this is required until 6853027 is fixed and text checking can do this for us.
     return character == '\'' || character == rightSingleQuotationMarkCharacter || character == hebrewPunctuationGershayimCharacter;
 }
 
 String stringWithRebalancedWhitespace(const String&, bool startIsStartOfParagraph, bool endIsEndOfParagraph);
 const String& nonBreakingSpaceString();
 
 }
 
 #endif