--- a/layout/style/CSSStyleSheet.cpp
+++ b/layout/style/CSSStyleSheet.cpp
@@ -760,26 +760,16 @@ CSSStyleSheet::Clone(CSSStyleSheet* aClo
 static void
 ListRules(const nsCOMArray<css::Rule>& aRules, FILE* aOut, int32_t aIndent)
 {
   for (int32_t index = aRules.Count() - 1; index >= 0; --index) {
     aRules.ObjectAt(index)->List(aOut, aIndent);
   }
 }
 
-struct ListEnumData {
-  ListEnumData(FILE* aOut, int32_t aIndent)
-    : mOut(aOut),
-      mIndent(aIndent)
-  {
-  }
-  FILE*   mOut;
-  int32_t mIndent;
-};
-
 void
 CSSStyleSheet::List(FILE* out, int32_t aIndent) const
 {
 
   int32_t index;
 
   // Indent
   nsAutoCString str;