Use [SameObject] for navigator.storage IDL

Author: foolip

storage.bs

@@ -209,7 +209,7 @@ user agent should alert the user and offer a way to clear <a>persistent buckets<
 <pre class=idl>
 [SecureContext]
 interface mixin NavigatorStorage {
-  readonly attribute StorageManager storage;
+  [SameObject] readonly attribute StorageManager storage;
 };
 Navigator includes NavigatorStorage;
 WorkerNavigator includes NavigatorStorage;