Fix a broken ASSERT in StylePropertySerializer.

Source/core/css/StylePropertySerializer.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Research In Motion Limited. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. 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.
@@ skipping 291 matching lines @@
             result.append(m_propertySet.propertyAt(repeatYPropertyIndex).cssText());
         }
     }
 
     ASSERT(!numDecls ^ !result.isEmpty());
     return result.toString();
 }
 
 String StylePropertySerializer::getPropertyValue(CSSPropertyID propertyID) const
 {
-    // Only enabled properties should be part of the style.
-    ASSERT(RuntimeCSSEnabled::isCSSPropertyEnabled(propertyID));
     // Shorthand and 4-values properties
     switch (propertyID) {
     case CSSPropertyBorderSpacing:
         return borderSpacingValue(borderSpacingShorthand());
     case CSSPropertyBackgroundPosition:
         return getLayeredShorthandValue(backgroundPositionShorthand());
     case CSSPropertyBackgroundRepeat:
         return getLayeredShorthandValue(backgroundRepeatShorthand());
     case CSSPropertyBackground:
         return getLayeredShorthandValue(backgroundShorthand());
@@ skipping 427 matching lines @@
         if (!result.isEmpty())
             result.append(' ');
         result.append(value);
     }
     if (isInitialOrInherit(commonValue))
         return commonValue;
     return result.isEmpty() ? String() : result.toString();
 }
 
 }