Stylesheet rule.cssText of content property should be quoted when the value is string.

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 842 matching lines @@
 
     return String::adopt(buffer);
 }
 
 template <unsigned characterCount>
 ALWAYS_INLINE static String formatNumber(double number, const char (&characters)[characterCount])
 {
     return formatNumber(number, characters, characterCount - 1);
 }
 
-String CSSPrimitiveValue::customCssText() const
+String CSSPrimitiveValue::customCssText(CssTextFormattingFlags formattingFlag) const
 {
     // FIXME: return the original value instead of a generated one (e.g. color
     // name if it was specified) - check what spec says about this
 
     if (m_hasCachedCSSText) {
         ASSERT(cssTextCache().contains(this));
         return cssTextCache().get(this);
     }
 
     String text;
@@ skipping 68 matching lines @@
         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;
             break;
         case CSS_STRING:
-            text = quoteCSSStringIfNeeded(m_value.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;
         case CSS_PROPERTY_ID:
             text = propertyName(m_value.propertyID);
             break;
@@ skipping 359 matching lines @@
         break;
     case CSS_CALC:
         info.addMember(m_value.calc, "value.calc");
         break;
     default:
         break;
     }
 }
 
 } // namespace WebCore