Convert USERSELECT_ALL to a runtime enabled feature.

Source/core/editing/htmlediting.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 130 matching lines @@
 inline Position lastPositionInOrAfterNode(Node* node)
 {
     if (!node)
         return Position();
     return editingIgnoresContent(node) ? positionAfterNode(node) : lastPositionInNode(node);
 }
 
 // comparision functions on Position
 
 int comparePositions(const Position&, const Position&);
+int comparePositions(const PositionWithAffinity&, const PositionWithAffinity&);
 
 // boolean functions on Position
 
 enum EUpdateStyle { UpdateStyle, DoNotUpdateStyle };
 bool isEditablePosition(const Position&, EditableType = ContentIsEditable, EUpdateStyle = UpdateStyle);
 bool isRichlyEditablePosition(const Position&, EditableType = ContentIsEditable);
 bool lineBreakExistsAtPosition(const Position&);
 bool isVisiblyAdjacent(const Position& first, const Position& second);
 bool isAtUnsplittableElement(const Position&);
 
@@ skipping 87 matching lines @@
     // FIXME: this is required until 6853027 is fixed and text checking can do this for us.
     return character == '\'' || character == rightSingleQuotationMark || character == hebrewPunctuationGershayim;
 }
 
 String stringWithRebalancedWhitespace(const String&, bool startIsStartOfParagraph, bool endIsEndOfParagraph);
 const String& nonBreakingSpaceString();
 
 }
 
 #endif