Remove all blimp network code.

blimp/net/connection_error_observer.h

-// Copyright 2015 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 BLIMP_NET_CONNECTION_ERROR_OBSERVER_H_
-#define BLIMP_NET_CONNECTION_ERROR_OBSERVER_H_
-
-namespace blimp {
-
-class ConnectionErrorObserver {
- public:
-  virtual ~ConnectionErrorObserver() {}
-
-  // Called when a blimp connection encounters an error.
-  // Negative |error| values correspond directly to net/ error codes.
-  // Positive values indicate the EndConnection.reason code specified
-  // by the peer during a "clean" disconnection.
-  virtual void OnConnectionError(int error) = 0;
-};
-
-}  // namespace blimp
-
-#endif  // BLIMP_NET_CONNECTION_ERROR_OBSERVER_H_