Suppress sequence checks in SyncFileSystem on the shutdown phase

chrome/browser/sync_file_system/drive_backend/sync_task_manager.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 CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_TASK_MANAGER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_TASK_MANAGER_H_
 
 #include <queue>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/sequence_checker.h"
+#include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/sync_file_system/drive_backend/task_dependency_manager.h"
 #include "chrome/browser/sync_file_system/sync_callbacks.h"
 #include "chrome/browser/sync_file_system/sync_status_code.h"
 #include "chrome/browser/sync_file_system/task_logger.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace tracked_objects {
@@ skipping 37 matching lines @@
         SyncStatusCode last_operation_status,
         bool last_operation_used_network) = 0;
 
     virtual void RecordTaskLog(scoped_ptr<TaskLogger::TaskLog> task_log) = 0;
   };
 
   // Runs at most |maximum_background_tasks| parallel as background tasks.
   // If |maximum_background_tasks| is zero, all task runs as foreground task.
   SyncTaskManager(base::WeakPtr<Client> client,
                   size_t maximum_background_task,
-                  const scoped_refptr<base::SequencedTaskRunner>& task_runner);
+                  const scoped_refptr<base::SequencedTaskRunner>& task_runner,
+                  const scoped_refptr<base::SequencedWorkerPool>& worker_pool);
   virtual ~SyncTaskManager();
 
   // This needs to be called to start task scheduling.
   // If |status| is not SYNC_STATUS_OK calling this may change the
   // service status. This should not be called more than once.
   void Initialize(SyncStatusCode status);
 
   // Schedules a task at the given priority.
   void ScheduleTask(const tracked_objects::Location& from_here,
                     const Task& task,
@@ skipping 29 matching lines @@
   // Note that this function once releases previous |task_blocker| before
   // applying new |task_blocker|.  So, any other task may be run before
   // invocation of |continuation|.
   static void UpdateTaskBlocker(scoped_ptr<SyncTaskToken> current_task_token,
                                 scoped_ptr<TaskBlocker> task_blocker,
                                 const Continuation& continuation);
 
   bool IsRunningTask(int64 task_token_id) const;
 
   void DetachFromSequence();
+  bool ShouldTrackTaskToken() const;
 
  private:
   struct PendingTask {
     base::Closure task;
     Priority priority;
     int64 seq;
 
     PendingTask();
     PendingTask(const base::Closure& task, Priority pri, int seq);
     ~PendingTask();
@@ skipping 55 matching lines @@
   // Absence of |token_| implies a task is running. Incoming tasks should
   // wait for the task to finish in |pending_tasks_| if |token_| is null.
   // Each task must take TaskToken instance from |token_| and must hold it
   // until it finished. And the task must return the instance through
   // NotifyTaskDone when the task finished.
   scoped_ptr<SyncTaskToken> token_;
 
   TaskDependencyManager dependency_manager_;
 
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
+  scoped_refptr<base::SequencedWorkerPool> worker_pool_;
   base::SequenceChecker sequence_checker_;
 
   base::WeakPtrFactory<SyncTaskManager> weak_ptr_factory_;;
 
   DISALLOW_COPY_AND_ASSIGN(SyncTaskManager);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_TASK_MANAGER_H_