Provide a mechanism for the GCM driver to send message receipts to GCM.

components/gcm_driver/gcm_driver_desktop.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_GCM_DRIVER_GCM_DRIVER_DESKTOP_H_
 #define COMPONENTS_GCM_DRIVER_GCM_DRIVER_DESKTOP_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 137 matching lines @@
   void DoRemoveInstanceIDData(const std::string& app_id);
   void DoGetInstanceIDData(const std::string& app_id);
   void DoGetToken(const std::string& app_id,
                   const std::string& authorized_entity,
                   const std::string& scope,
                   const std::map<std::string, std::string>& options);
   void DoDeleteToken(const std::string& app_id,
                      const std::string& authorized_entity,
                      const std::string& scope);
 
+  void DoSendMessageReceipt(
+      const MessageReceiptCallback& optional_receipt_callback,
+      GCMMessageStatus status);
+
   // Callbacks posted from IO thread to UI thread.
   void MessageReceived(const std::string& app_id,
-                       const IncomingMessage& message);
+                       const IncomingMessage& message,
+                       const MessageReceiptCallback& optional_receipt_callback);
   void MessagesDeleted(const std::string& app_id);
   void MessageSendError(const std::string& app_id,
                         const GCMClient::SendErrorDetails& send_error_details);
   void SendAcknowledged(const std::string& app_id,
                         const std::string& message_id);
   void GCMClientReady(const std::vector<AccountMapping>& account_mappings,
                       const base::Time& last_token_fetch_time);
   void OnConnected(const net::IPEndPoint& ip_endpoint);
   void OnDisconnected();
   void OnStoreReset();
@@ skipping 65 matching lines @@
 
   // Used to pass a weak pointer to the IO worker.
   base::WeakPtrFactory<GCMDriverDesktop> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GCMDriverDesktop);
 };
 
 }  // namespace gcm
 
 #endif  // COMPONENTS_GCM_DRIVER_GCM_DRIVER_DESKTOP_H_