Revert of Fix serialization of alias_for properties

Source/core/css/CSSPrimitiveValue.cpp

Index: Source/core/css/CSSPrimitiveValue.cpp
diff --git a/Source/core/css/CSSPrimitiveValue.cpp b/Source/core/css/CSSPrimitiveValue.cpp
index cd62e28952a5d27259e64ab93a2e3c01690116d2..60b83526c917d22055691e2bc2febfba2c2f4563 100644
--- a/Source/core/css/CSSPrimitiveValue.cpp
+++ b/Source/core/css/CSSPrimitiveValue.cpp
@@ -259,6 +259,12 @@
 
 static const AtomicString& propertyName(CSSPropertyID propertyID)
 {
+    ASSERT_ARG(propertyID, propertyID >= 0);
+    ASSERT_ARG(propertyID, (propertyID >= firstCSSProperty && propertyID < firstCSSProperty + numCSSProperties));
+
+    if (propertyID < 0)
+        return nullAtom;
+
     return getPropertyNameAtomicString(propertyID);
 }