[GCM] Adding the OnSendAcknowledgement event

components/gcm_driver/default_gcm_app_handler.h

 // Copyright (c) 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_DEFAULT_GCM_APP_HANDLER_H_
 #define COMPONENTS_GCM_DRIVER_DEFAULT_GCM_APP_HANDLER_H_
 
 #include "base/compiler_specific.h"
 #include "components/gcm_driver/gcm_app_handler.h"
 
 namespace gcm {
 
 // The default app handler that is triggered when there is no registered app
 // handler for an application id.
 class DefaultGCMAppHandler : public GCMAppHandler {
  public:
   DefaultGCMAppHandler();
   virtual ~DefaultGCMAppHandler();
 
   // Overridden from GCMAppHandler:
   virtual void ShutdownHandler() OVERRIDE;
   virtual void OnMessage(const std::string& app_id,
                          const GCMClient::IncomingMessage& message) OVERRIDE;
   virtual void OnMessagesDeleted(const std::string& app_id) OVERRIDE;
   virtual void OnSendError(
       const std::string& app_id,
       const GCMClient::SendErrorDetails& send_error_details) OVERRIDE;
+  virtual void OnSendAcknowledged(const std::string& app_id,
+                                  const std::string& message_id) OVERRIDE;
   virtual void OnConnected(const net::IPEndPoint& ip_endpoint) OVERRIDE;
   virtual void OnDisconnected() OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DefaultGCMAppHandler);
 };
 
 }  // namespace gcm
 
 #endif  // COMPONENTS_GCM_DRIVER_DEFAULT_GCM_APP_HANDLER_H_