[CSS Grid Layout] Use CSS_FR for flexible lengths instead of CSS_DIMENSION

Source/core/css/CSSPrimitiveValue.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 970 matching lines @@
         case CSS_HZ:
             text = formatNumber(m_value.num, "hz");
             break;
         case CSS_KHZ:
             text = formatNumber(m_value.num, "khz");
             break;
         case CSS_TURN:
             text = formatNumber(m_value.num, "turn");
             break;
         case CSS_DIMENSION:
-            text = m_value.string;
+            // FIXME

[Julien - ping for review, 2013/09/13 16:44:51]

I don't like this change, even if you are reverting the code to its original
state for one reason: the FIXME is *not actionable*. If I read it, I have no
clue what I should (or shouldn't) do.

I would just put the following instead:

// FIXME: We currently don't handle CSS_DIMENSION properly as we don't store the
actual dimension, just the numeric value as a string.

             break;
         case CSS_STRING:
             text = formattingFlag == AlwaysQuoteCSSString ? quoteCSSString(m_value.string) : quoteCSSStringIfNeeded(m_value.string);
             break;
         case CSS_URI:
             text = "url(" + quoteCSSURLIfNeeded(m_value.string) + ")";
             break;
         case CSS_VALUE_ID:
             text = valueName(m_value.valueID);
             break;
@@ skipping 330 matching lines @@
         return m_value.parserOperator == other.m_value.parserOperator;
     case CSS_CALC:
         return m_value.calc && other.m_value.calc && m_value.calc->equals(*other.m_value.calc);
     case CSS_SHAPE:
         return m_value.shape && other.m_value.shape && m_value.shape->equals(*other.m_value.shape);
     }
     return false;
 }
 
 } // namespace WebCore