Use DEFINE_CSS_VALUE_TYPE_CASTS instead of using manual type cast function for CSSShaderValue

Source/core/css/CSSValue.cpp

 /*
  * Copyright (C) 2011 Andreas Kling (kling@webkit.org)
  *
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 409 matching lines @@
     case CSSFilterClass:
         delete static_cast<CSSFilterValue*>(this);
         return;
     case CSSArrayFunctionValueClass:
         delete static_cast<CSSArrayFunctionValue*>(this);
         return;
     case CSSMixFunctionValueClass:
         delete static_cast<CSSMixFunctionValue*>(this);
         return;
     case CSSShaderClass:
-        delete static_cast<CSSShaderValue*>(this);
+        delete toCSSShaderValue(this);
         return;
     case VariableClass:
         delete toCSSVariableValue(this);
         return;
     case SVGColorClass:
         delete static_cast<SVGColor*>(this);
         return;
     case SVGPaintClass:
         delete static_cast<SVGPaint*>(this);
         return;
@@ skipping 28 matching lines @@
         return static_cast<const SVGColor*>(this)->cloneForCSSOM();
     case SVGPaintClass:
         return static_cast<const SVGPaint*>(this)->cloneForCSSOM();
     default:
         ASSERT(!isSubtypeExposedToCSSOM());
         return TextCloneCSSValue::create(classType(), cssText());
     }
 }
 
 }