Remove CSS_SHADERS compile-time flag.

Source/WebCore/css/CSSRule.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2006, 2007, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Andreas Kling (kling@webkit.org)
  *
  * 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 41 matching lines @@
         WEBKIT_KEYFRAME_RULE,
 #if ENABLE(CSS3_CONDITIONAL_RULES)
         SUPPORTS_RULE = 12,
 #endif
 #if ENABLE(CSS_DEVICE_ADAPTATION)
         WEBKIT_VIEWPORT_RULE = 15,
 #endif
 #if ENABLE(CSS_REGIONS)
         WEBKIT_REGION_RULE = 16,
 #endif
-#if ENABLE(CSS_SHADERS)
         WEBKIT_FILTER_RULE = 17,
-#endif
 #if ENABLE(SHADOW_DOM)
         HOST_RULE = 1001,
 #endif
     };
 
     virtual Type type() const = 0;
     virtual String cssText() const = 0;
     virtual void reattach(StyleRuleBase*) = 0;
     virtual void reportMemoryUsage(MemoryObjectInfo*) const;
 
@@ skipping 40 matching lines @@
 
     union {
         CSSRule* m_parentRule;
         CSSStyleSheet* m_parentStyleSheet;
     };
 };
 
 } // namespace WebCore
 
 #endif // CSSRule_h