Remove CSS_SHADERS compile-time flag.

Source/WebCore/css/WebKitCSSMixFunctionValue.h

 /*
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer.
@@ skipping 12 matching lines @@
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #ifndef WebKitCSSMixFunctionValue_h
 #define WebKitCSSMixFunctionValue_h
 
-#if ENABLE(CSS_SHADERS)
-
 #include "CSSValueList.h"
 #include <wtf/PassRefPtr.h>
 
 namespace WebCore {
 
 class WebKitCSSMixFunctionValue : public CSSValueList {
 public:
     static PassRefPtr<WebKitCSSMixFunctionValue> create()
     {
         return adoptRef(new WebKitCSSMixFunctionValue());
     }
 
     String customCssText() const;
 
     PassRefPtr<WebKitCSSMixFunctionValue> cloneForCSSOM() const;
 
     bool equals(const WebKitCSSMixFunctionValue&) const;
 
     void reportDescendantMemoryUsage(MemoryObjectInfo*) const;
 
 private:
     WebKitCSSMixFunctionValue();
     WebKitCSSMixFunctionValue(const WebKitCSSMixFunctionValue& cloneFrom);
 };
     
 } // namespace WebCore
 
-#endif // ENABLE(CSS_SHADERS)
 
 #endif