Adding support for pre-sent messages

components/copresence/handlers/gcm_handler_impl.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_COPRESENCE_HANDLERS_GCM_HANDLER_IMPL_H_
 #define COMPONENTS_COPRESENCE_HANDLERS_GCM_HANDLER_IMPL_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/cancelable_callback.h"
 #include "components/copresence/handlers/gcm_handler.h"
+#include "components/copresence/public/copresence_constants.h"
 #include "components/gcm_driver/gcm_app_handler.h"
 #include "components/gcm_driver/gcm_client.h"
 
 namespace gcm {
 class GCMDriver;
 }
 
 namespace copresence {
 
 class DirectiveHandler;
 
 // This class handles GCM messages from the Copresence server.
 class GCMHandlerImpl final : public GCMHandler,
                              public gcm::GCMAppHandler {
  public:
   // Callback to report that registration has completed.
   // Returns an empty ID if registration failed.
   using RegistrationCallback = base::Callback<void(const std::string&)>;
 
   static const char kCopresenceAppId[];
   static const char kCopresenceSenderId[];
   static const char kGcmMessageKey[];
 
   // |gcm_driver| is required, but may disappear if we get a ShutdownHandler()
   // call first. |directive_handler| must outlive us. The caller owns both.
   GCMHandlerImpl(gcm::GCMDriver* gcm_driver,
-                 DirectiveHandler* directive_handler);
+                 DirectiveHandler* directive_handler,
+                 const MessagesCallback& new_messages_callback);
   ~GCMHandlerImpl() override;
 
   // GCMHandler override.
   void GetGcmId(const RegistrationCallback& callback) override;
 
  private:
   friend class GCMHandlerTest;
 
   // GCMAppHandler overrides
   void ShutdownHandler() override;
   void OnMessage(const std::string& app_id,
                  const gcm::GCMClient::IncomingMessage& message) override;
   void OnMessagesDeleted(const std::string& app_id) override;
   void OnSendError(
       const std::string& /* app_id */,
       const gcm::GCMClient::SendErrorDetails& /* send_error_details */)
       override;
   void OnSendAcknowledged(const std::string& /* app_id */,
                           const std::string& /* message_id */) override;
   bool CanHandle(const std::string& app_id) const override;
 
   // GCM Registration has finished. Notify clients as appropriate.
   void RegistrationComplete(const std::string& registration_id,
                             gcm::GCMClient::Result result);
 
   gcm::GCMDriver* driver_;
   DirectiveHandler* const directive_handler_;
+  MessagesCallback new_messages_callback_;
 
   std::string gcm_id_;
   std::vector<RegistrationCallback> pending_id_requests_;
 
   base::CancelableCallback<void(const std::string&,
                                 gcm::GCMClient::Result)> registration_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(GCMHandlerImpl);
 };
 
 }  // namespace copresence
 
 #endif  // COMPONENTS_COPRESENCE_HANDLERS_GCM_HANDLER_IMPL_H_