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

remoting/protocol/client_message_dispatcher.cc

Index: remoting/protocol/client_message_dispatcher.cc
diff --git a/remoting/protocol/client_message_dispatcher.cc b/remoting/protocol/client_message_dispatcher.cc
index 31123064f387d112e0efd933a41227df91a1bb0d..446cd9d9fc47758fd2b03d521c3acf4bf616e48e 100644
--- a/remoting/protocol/client_message_dispatcher.cc
+++ b/remoting/protocol/client_message_dispatcher.cc
@@ -40,18 +40,8 @@ void ClientMessageDispatcher::Initialize(
 
 void ClientMessageDispatcher::OnControlMessageReceived(
     ControlMessage* message, const base::Closure& done_task) {
-  if (message->has_begin_session_response()) {
-    const BeginSessionResponse& response = message->begin_session_response();
-    if (response.has_login_status() &&
-        response.login_status().has_success()) {
-      client_stub_->BeginSessionResponse(
-          &response.login_status(), done_task);
-      return;
-    }
-  }
 
   LOG(WARNING) << "Invalid control message received.";
-
   done_task.Run();
 }