Generate toCSSFooValue() for CSS child values

Source/core/css/resolver/StyleBuilderCustom.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 35 matching lines @@
     static Length convertLengthMaxSizing(StyleResolverState&, CSSValue*);
     static LengthPoint convertLengthPoint(StyleResolverState&, CSSValue*);
     static LengthSize convertRadius(StyleResolverState&, CSSValue*);
     static float convertSpacing(StyleResolverState&, CSSValue*);
     template <CSSValueID IdForNone> static AtomicString convertString(StyleResolverState&, CSSValue*);
 };
 
 template <typename T>
 T StyleBuilderConverter::convertComputedLength(StyleResolverState& state, CSSValue* value)
 {
-    CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
     float zoom = state.style()->effectiveZoom();
-    return primitiveValue->computeLength<T>(state.style(), state.rootElementStyle(), zoom);
+    return toCSSPrimitiveValue(value)->computeLength<T>(state.style(), state.rootElementStyle(), zoom);
 }
 
 template <typename T>
 T StyleBuilderConverter::convertLineWidth(StyleResolverState& state, CSSValue* value)
 {
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
     CSSValueID valueID = primitiveValue->getValueID();
     if (valueID == CSSValueThin)
         return 1;
     if (valueID == CSSValueMedium)
@@ skipping 21 matching lines @@
 {
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
     if (primitiveValue->getValueID() == IdForNone)
         return nullAtom;
     return primitiveValue->getStringValue();
 }
 
 } // namespace WebCore
 
 #endif