Introduce a layering in the invalidation component as public and impl

components/invalidation/gcm_network_channel_delegate.h

-// Copyright 2014 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 COMPONENTS_INVALIDATION_GCM_NETWORK_CHANNEL_DELEGATE_H_
-#define COMPONENTS_INVALIDATION_GCM_NETWORK_CHANNEL_DELEGATE_H_
-
-#include <string>
-
-#include "base/callback.h"
-#include "components/gcm_driver/gcm_client.h"
-
-class GoogleServiceAuthError;
-
-namespace syncer {
-
-// Delegate for GCMNetworkChannel.
-// GCMNetworkChannel needs Register to register with GCM client and obtain gcm
-// registration id. This id is used for building URL to cache invalidation
-// endpoint.
-// It needs RequestToken and InvalidateToken to get access token to include it
-// in HTTP message to server.
-// GCMNetworkChannel lives on IO thread therefore calls will be made on IO
-// thread and callbacks should be invoked there as well.
-class GCMNetworkChannelDelegate {
- public:
-  typedef base::Callback<void(const GoogleServiceAuthError& error,
-                              const std::string& token)> RequestTokenCallback;
-  typedef base::Callback<void(const std::string& registration_id,
-                              gcm::GCMClient::Result result)> RegisterCallback;
-  typedef base::Callback<void(const std::string& message,
-                              const std::string& echo_token)> MessageCallback;
-  typedef base::Callback<void(bool online)> ConnectionStateCallback;
-
-  virtual ~GCMNetworkChannelDelegate() {}
-
-  virtual void Initialize(ConnectionStateCallback callback) = 0;
-  // Request access token. Callback should be called either with access token or
-  // error code.
-  virtual void RequestToken(RequestTokenCallback callback) = 0;
-  // Invalidate access token that was rejected by server.
-  virtual void InvalidateToken(const std::string& token) = 0;
-
-  // Request registration_id from GCMService. Callback should be called with
-  // either registration id or error code.
-  virtual void Register(RegisterCallback callback) = 0;
-  // Provide callback for incoming messages from GCM.
-  virtual void SetMessageReceiver(MessageCallback callback) = 0;
-};
-}  // namespace syncer
-
-#endif  // COMPONENTS_INVALIDATION_GCM_NETWORK_CHANNEL_DELEGATE_H_