Access Session::config() and Session::jid() on the correct thread only.

remoting/host/heartbeat_sender.cc

Index: remoting/host/heartbeat_sender.cc
diff --git a/remoting/host/heartbeat_sender.cc b/remoting/host/heartbeat_sender.cc
index 32ddd495f2219f6ab69b1b81c02cdf1a86e2a585..1f285212f5cd0f032fe220d4beb509e268410404 100644
--- a/remoting/host/heartbeat_sender.cc
+++ b/remoting/host/heartbeat_sender.cc
@@ -90,10 +90,8 @@ void HeartbeatSender::OnSignallingDisconnected() {
 // Ignore any notifications other than signalling
 // connected/disconnected events.
 void HeartbeatSender::OnAccessDenied() { }
-void HeartbeatSender::OnClientAuthenticated(
-    remoting::protocol::ConnectionToClient* client) { }
-void HeartbeatSender::OnClientDisconnected(
-    remoting::protocol::ConnectionToClient* client) { }
+void HeartbeatSender::OnClientAuthenticated(const std::string& jid) { }
+void HeartbeatSender::OnClientDisconnected(const std::string& jid) { }
 void HeartbeatSender::OnShutdown() { }
 
 void HeartbeatSender::DoSendStanza() {