Use toCSSFooValue() generation macro for CSSInheritedValue, CSSVariableValue and CSSGridTemplateVal…

Source/core/css/CSSValue.cpp

Index: Source/core/css/CSSValue.cpp
diff --git a/Source/core/css/CSSValue.cpp b/Source/core/css/CSSValue.cpp
index 5d765047b68e4a244ac3f63d25a24879141f7a17..3770529d04cb9d53f2b44fec0d5516020ca5398f 100644
--- a/Source/core/css/CSSValue.cpp
+++ b/Source/core/css/CSSValue.cpp
@@ -376,13 +376,13 @@ void CSSValue::destroy()
         delete toCSSImageValue(this);
         return;
     case InheritedClass:
-        delete static_cast<CSSInheritedValue*>(this);
+        delete toCSSInheritedValue(this);
         return;
     case InitialClass:
         delete static_cast<CSSInitialValue*>(this);
         return;
     case GridTemplateClass:
-        delete static_cast<CSSGridTemplateValue*>(this);
+        delete toCSSGridTemplateValue(this);
         return;
     case PrimitiveClass:
         delete toCSSPrimitiveValue(this);