Cleanup error handling in the client plugin.

remoting/protocol/errors.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_PROTOCOL_ERROR_H_
+#define REMOTING_PROTOCOL_ERROR_H_
+
+namespace remoting {
+namespace protocol {
+
+enum ErrorCode {
+  OK = 0,
+  PEER_IS_OFFLINE,
+  SESSION_REJECTED,
+  INCOMPATIBLE_PROTOCOL,
+  AUTHENTICATION_FAILED,
+  CHANNEL_CONNECTION_ERROR,
+  SIGNALING_ERROR,
+  SIGNALING_TIMEOUT,
+  UNKNOWN_ERROR,
+};
+
+}  // namespace protocol
+}  // namespace remoting
+
+#endif  // REMOTING_PROTOCOL_ERROR_H_