Now using use along with enums, as per https://github.com/rust-lang/rust/pull/18973.

src/header/common/upgrade.rs

@@ -3,6 +3,8 @@ use std::fmt::{mod, Show};
 use std::str::FromStr;
 use super::util::{from_comma_delimited, fmt_comma_delimited};
 
+use self::Protocol::{WebSocket, ProtocolExt};
+
 /// The `Upgrade` header.
 #[deriving(Clone, PartialEq, Show)]
 pub struct Upgrade(Vec<Protocol>);