Remove old Authentication code that we don't use or need.

remoting/protocol/client_control_sender.cc

Index: remoting/protocol/client_control_sender.cc
diff --git a/remoting/protocol/client_control_sender.cc b/remoting/protocol/client_control_sender.cc
index 1c16cf311d97dc46b3f4efb66286349d0dbcec66..08fd9250272db0c5bbf25370cae44a68ac724b22 100644
--- a/remoting/protocol/client_control_sender.cc
+++ b/remoting/protocol/client_control_sender.cc
@@ -25,13 +25,6 @@ ClientControlSender::ClientControlSender(base::MessageLoopProxy* message_loop,
 ClientControlSender::~ClientControlSender() {
 }
 
-void ClientControlSender::BeginSessionResponse(const LocalLoginStatus* msg,
-                                               const base::Closure& done) {
-  protocol::ControlMessage message;
-  message.mutable_begin_session_response()->mutable_login_status()->
-      CopyFrom(*msg);
-  buffered_writer_->Write(SerializeAndFrameMessage(message), done);
-}
 
 void ClientControlSender::Close() {
   buffered_writer_->Close();