Implement a ProfilerActor struct.

This is sufficient to make the profiler tab show up in Firefox's devtools.

components/devtools/actors/profiler.rs

@@ -0,0 +1,34 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use actor::{Actor, ActorRegistry};
+
+use rustc_serialize::json;
+use std::net::TcpStream;
+
+pub struct ProfilerActor {
+    name: String,
+}
+
+impl Actor for ProfilerActor {
+    fn name(&self) -> String {
+        self.name.clone()
+    }
+
+    fn handle_message(&self,
+                      _registry: &ActorRegistry,
+                      _msg_type: &str,
+                      _msg: &json::Object,
+                      _stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(false)
+    }
+}
+
+impl ProfilerActor {
+    pub fn new(name: String) -> ProfilerActor {
+        ProfilerActor {
+            name: name,
+        }
+    }
+}

components/devtools/actors/tab.rs

@@ -62,6 +62,7 @@ pub struct TabActorMsg {
     consoleActor: String,
     inspectorActor: String,
     timelineActor: String,
+    profilerActor: String,
 }
 
 pub struct TabActor {
@@ -71,6 +72,7 @@ pub struct TabActor {
     pub console: String,
     pub inspector: String,
     pub timeline: String,
+    pub profiler: String,
 }
 
 impl Actor for TabActor {
@@ -147,6 +149,7 @@ impl TabActor {
             consoleActor: self.console.clone(),
             inspectorActor: self.inspector.clone(),
             timelineActor: self.timeline.clone(),
+            profilerActor: self.profiler.clone(),
         }
     }
 }