[GCM] Run InstanceIDImpl callbacks asynchronously

components/gcm_driver/gcm_driver_desktop.cc

 // 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.
 
 #include "components/gcm_driver/gcm_driver_desktop.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/sequenced_task_runner.h"
 #include "base/task_runner_util.h"
 #include "base/threading/sequenced_worker_pool.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "components/gcm_driver/gcm_account_mapper.h"
 #include "components/gcm_driver/gcm_app_handler.h"
 #include "components/gcm_driver/gcm_channel_status_syncer.h"
 #include "components/gcm_driver/gcm_client_factory.h"
 #include "components/gcm_driver/gcm_delayed_task_controller.h"
 #include "components/gcm_driver/instance_id/instance_id_impl.h"
 #include "components/gcm_driver/system_encryptor.h"
 #include "google_apis/gcm/engine/account_mapping.h"
 #include "net/base/ip_endpoint.h"
@@ skipping 1080 matching lines @@
 }
 
 void GCMDriverDesktop::GetInstanceIDData(
     const std::string& app_id,
     const GetInstanceIDDataCallback& callback) {
   DCHECK(!get_instance_id_data_callbacks_.count(app_id));
   DCHECK(ui_thread_->RunsTasksOnCurrentThread());
 
   GCMClient::Result result = EnsureStarted(GCMClient::IMMEDIATE_START);
   if (result != GCMClient::SUCCESS) {
-    callback.Run(std::string(), std::string());
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(callback, std::string(), std::string()));
     return;
   }
 
   get_instance_id_data_callbacks_[app_id] = callback;
 
   // Delay the operation until GCMClient is ready.
   if (!delayed_task_controller_->CanRunTaskWithoutDelay()) {
     delayed_task_controller_->AddTask(
         base::Bind(&GCMDriverDesktop::DoGetInstanceIDData,
                    weak_ptr_factory_.GetWeakPtr(),
@@ skipping 308 matching lines @@
 
   if (std::get<1>(a) < std::get<1>(b))
     return true;
   if (std::get<1>(a) > std::get<1>(b))
     return false;
 
   return std::get<2>(a) < std::get<2>(b);
 }
 
 }  // namespace gcm