Remove all blimp client code.

blimp/client/core/settings/blimp_settings_delegate.h

-// Copyright 2016 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_CLIENT_CORE_SETTINGS_BLIMP_SETTINGS_DELEGATE_H_
-#define BLIMP_CLIENT_CORE_SETTINGS_BLIMP_SETTINGS_DELEGATE_H_
-
-#include "base/macros.h"
-
-namespace blimp {
-namespace client {
-
-class ConnectionStatus;
-class IdentitySource;
-
-// BlimpSettingsDelegate is an interface that provides functionalities needed
-// by core/settings.
-class BlimpSettingsDelegate {
- public:
-  // Get IdentitySource that provides sign in state change.
-  virtual IdentitySource* GetIdentitySource() = 0;
-
-  // Get the connection status that provides engine IP and broadcasts network
-  // events.
-  virtual ConnectionStatus* GetConnectionStatus() = 0;
-};
-
-}  // namespace client
-}  // namespace blimp
-
-#endif  // BLIMP_CLIENT_CORE_SETTINGS_BLIMP_SETTINGS_DELEGATE_H_