Implement a dummy protocolDescription in the root actor

components/devtools/actors/performance.rs

@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use actor::{Actor, ActorMessageStatus, ActorRegistry};
-use protocol::JsonPacketStream;
+use protocol::{ActorDescription, JsonPacketStream, Method};
 use serde_json::Value;
 use std::collections::BTreeMap;
 use std::net::TcpStream;
@@ -70,4 +70,12 @@ impl PerformanceActor {
             name: name,
         }
     }
+
+    pub fn description() -> ActorDescription {
+        ActorDescription {
+            category: "actor",
+            typeName: "performance",
+            methods: vec![],
+        }
+    }
 }