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..d53b82e95f9135d809331792501fe071e9a9392d 100644
--- a/remoting/protocol/client_control_sender.cc
+++ b/remoting/protocol/client_control_sender.cc
@@ -20,18 +20,17 @@ ClientControlSender::ClientControlSender(base::MessageLoopProxy* message_loop,
                                          net::Socket* socket)
     : buffered_writer_(new BufferedSocketWriter(message_loop)) {
   buffered_writer_->Init(socket, BufferedSocketWriter::WriteFailedCallback());
+
+  // Write legacy BeginSession message.
+  protocol::ControlMessage message;
+  message.mutable_begin_session_deprecated()->mutable_login_status()->
+      set_success(true);
+  buffered_writer_->Write(SerializeAndFrameMessage(message), base::Closure());
 }
 
 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();