Replace compile flag with runtime check for text-underline-position

Source/core/css/CSSProperty.cpp

 /**
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
  *
  * 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 321 matching lines @@
     case CSSPropertyWebkitLineAlign:
     case CSSPropertyWebkitLineBoxContain:
     case CSSPropertyWebkitLineBreak:
     case CSSPropertyWebkitLineGrid:
     case CSSPropertyWebkitLineSnap:
     case CSSPropertyWebkitPrintColorAdjust:
     case CSSPropertyWebkitRtlOrdering:
     case CSSPropertyWebkitRubyPosition:
     case CSSPropertyWebkitTapHighlightColor:
     case CSSPropertyWebkitTextCombine:
-#if ENABLE(CSS3_TEXT)
-    case CSSPropertyWebkitTextUnderlinePosition:
-#endif // CSS3_TEXT
+    case CSSPropertyTextUnderlinePosition:
     case CSSPropertyWebkitTextDecorationsInEffect:
     case CSSPropertyWebkitTextEmphasis:
     case CSSPropertyWebkitTextEmphasisColor:
     case CSSPropertyWebkitTextEmphasisPosition:
     case CSSPropertyWebkitTextEmphasisStyle:
     case CSSPropertyWebkitTextFillColor:
     case CSSPropertyWebkitTextOrientation:
     case CSSPropertyWebkitTextSecurity:
     case CSSPropertyWebkitTextStroke:
     case CSSPropertyWebkitTextStrokeColor:
@@ skipping 328 matching lines @@
         return false;
     case CSSPropertyInvalid:
         ASSERT_NOT_REACHED();
         return false;
     }
     ASSERT_NOT_REACHED();
     return false;
 }
 
 } // namespace WebCore