[GCM] Support registration before unregistration finishes

components/gcm_driver/gcm_driver.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_H_
 #define COMPONENTS_GCM_DRIVER_GCM_DRIVER_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "components/gcm_driver/default_gcm_app_handler.h"
 #include "components/gcm_driver/gcm_client.h"
 
 namespace gcm {
 
 class GCMAppHandler;
 class GCMConnectionObserver;
 struct AccountMapping;
 
@@ skipping 141 matching lines @@
   // Runs the Send callback.
   void SendFinished(const std::string& app_id,
                     const std::string& message_id,
                     GCMClient::Result result);
 
   bool HasRegisterCallback(const std::string& app_id);
 
   void ClearCallbacks();
 
  private:
-  // Should be called when an app with |app_id| is trying to un/register.
-  // Checks whether another un/registration is in progress.
-  bool IsAsyncOperationPending(const std::string& app_id) const;
+  // Called after unregistration completes in order to trigger the pending
+  // registration.
+  void RegisterAfterUnregister(
+      const std::string& app_id,
+      const std::vector<std::string>& normalized_sender_ids,
+      const UnregisterCallback& unregister_callback,
+      GCMClient::Result result);
 
   // Callback map (from app_id to callback) for Register.
   std::map<std::string, RegisterCallback> register_callbacks_;
 
   // Callback map (from app_id to callback) for Unregister.
   std::map<std::string, UnregisterCallback> unregister_callbacks_;
 
   // Callback map (from <app_id, message_id> to callback) for Send.
   std::map<std::pair<std::string, std::string>, SendCallback> send_callbacks_;
 
   // App handler map (from app_id to handler pointer).
   // The handler is not owned.
   GCMAppHandlerMap app_handlers_;
 
   // The default handler when no app handler can be found in the map.
   DefaultGCMAppHandler default_app_handler_;
 
+  base::WeakPtrFactory<GCMDriver> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(GCMDriver);
 };
 
 }  // namespace gcm
 
 #endif  // COMPONENTS_GCM_DRIVER_GCM_DRIVER_H_