Make sure to use CSSValueID and CSSPropertyID rather than integers.

Source/core/css/CSSParserValues.h

Index: Source/core/css/CSSParserValues.h
diff --git a/Source/core/css/CSSParserValues.h b/Source/core/css/CSSParserValues.h
index 46c0c3d19bd9635a6cb7af7053d83f6123e4b24c..7d90ef424002e983e2c23530c1424412a161c898 100644
--- a/Source/core/css/CSSParserValues.h
+++ b/Source/core/css/CSSParserValues.h
@@ -21,11 +21,12 @@
 #ifndef CSSParserValues_h
 #define CSSParserValues_h
 
+#include "CSSValueKeywords.h"
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/CSSSelector.h"
 #include "core/css/CSSValueList.h"
-#include <wtf/text/AtomicString.h>
-#include <wtf/text/WTFString.h>
+#include "wtf/text/AtomicString.h"
+#include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
@@ -126,7 +127,7 @@ struct CSSParserString {
 struct CSSParserFunction;
 
 struct CSSParserValue {
-    int id;
+    CSSValueID id;
     bool isInt;
     union {
         double fValue;
@@ -239,7 +240,7 @@ inline bool CSSParserSelector::hasShadowPseudo() const
 
 inline void CSSParserValue::setFromNumber(double value, int unit)
 {
-    id = 0;
+    id = CSSValueInvalid;
     isInt = false;
     fValue = value;
     this->unit = unit;