Implementation of CSS3 nav-up/down/left/right properties from CSS3 UI.

Source/core/css/CSSGrammar.y.in

 /*
  *  Copyright (C) 2002-2003 Lars Knoll (knoll@kde.org)
  *  Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *  Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *  Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  *  Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
@@ skipping 1624 matching lines @@
       $$.id = cssValueKeywordID($1);
       $$.unit = CSSPrimitiveValue::CSS_IDENT;
       $$.string = $1;
   }
   /* We might need to actually parse the number from a dimension, but we can't just put something that uses $$.string into unary_term. */
   | DIMEN maybe_space { $$.id = CSSValueInvalid; $$.string = $1; $$.unit = CSSPrimitiveValue::CSS_DIMENSION; }
   | unary_operator DIMEN maybe_space { $$.id = CSSValueInvalid; $$.string = $2; $$.unit = CSSPrimitiveValue::CSS_DIMENSION; }
   | URI maybe_space { $$.id = CSSValueInvalid; $$.string = $1; $$.unit = CSSPrimitiveValue::CSS_URI; }
   | UNICODERANGE maybe_space { $$.id = CSSValueInvalid; $$.string = $1; $$.unit = CSSPrimitiveValue::CSS_UNICODE_RANGE; }
   | HEX maybe_space { $$.id = CSSValueInvalid; $$.string = $1; $$.unit = CSSPrimitiveValue::CSS_PARSER_HEXCOLOR; }
+  | IDSEL maybe_space { $$.id = CSSValueInvalid; $$.string = $1; $$.unit = CSSPrimitiveValue::CSS_STRING; }
   | '#' maybe_space { $$.id = CSSValueInvalid; $$.string = CSSParserString(); $$.unit = CSSPrimitiveValue::CSS_PARSER_HEXCOLOR; } /* Handle error case: "color: #;" */
   | VARFUNCTION maybe_space IDENT closing_parenthesis maybe_space {
       $$.id = CSSValueInvalid;
       $$.string = $3;
       $$.unit = CSSPrimitiveValue::CSS_VARIABLE_NAME;
   }
   | VARFUNCTION maybe_space expr_recovery closing_parenthesis {
       YYERROR;
   }
   /* FIXME: according to the specs a function can have a unary_operator in front. I know no case where this makes sense */
@@ skipping 221 matching lines @@
 
 rule_error_recovery:
     /* empty */
   | rule_error_recovery error
   | rule_error_recovery invalid_square_brackets_block
   | rule_error_recovery invalid_parentheses_block
     ;
 
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