Support for latest WebIDL for indexed property getters.

Source/core/css/StyleSheetList.idl

Index: Source/core/css/StyleSheetList.idl
diff --git a/Source/core/css/StyleSheetList.idl b/Source/core/css/StyleSheetList.idl
index c9c044e3a73bad0209ab34902780a251628f57fa..fce41cf9b8166590658da037ffe72398eeac64be 100644
--- a/Source/core/css/StyleSheetList.idl
+++ b/Source/core/css/StyleSheetList.idl
@@ -21,11 +21,10 @@
 // Introduced in DOM Level 2:
 [
     GenerateIsReachable=ImplDocument,
-    IndexedGetter,
     CustomNamedGetter,
     ImplementationLacksVTable
 ] interface StyleSheetList {
     readonly attribute unsigned long    length;
-    StyleSheet         item([Default=Undefined] optional unsigned long index);
+    getter StyleSheet         item([Default=Undefined] optional unsigned long index);
 };