[fsp] Simplify aborting logic.

chrome/browser/chromeos/file_system_provider/throttled_file_system.h

 // Copyright 2015 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_CHROMEOS_FILE_SYSTEM_PROVIDER_THROTTLED_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_THROTTLED_FILE_SYSTEM_H_
 
 #include <set>
 #include <string>
 
@@ skipping 104 matching lines @@
   virtual void Notify(
       const base::FilePath& entry_path,
       bool recursive,
       storage::WatcherManager::ChangeType change_type,
       scoped_ptr<ProvidedFileSystemObserver::Changes> changes,
       const std::string& tag,
       const storage::AsyncFileUtil::StatusCallback& callback) override;
   virtual base::WeakPtr<ProvidedFileSystemInterface> GetWeakPtr() override;
 
  private:
+  // Called when an operation enqueued with |queue_token| is aborted.
+  void Abort(int queue_token);
+
   // Called when opening a file is completed with either a success or an error.
   void OnOpenFileCompleted(int queue_token,
                            const OpenFileCallback& callback,
                            int file_handle,
                            base::File::Error result);
 
   // Called when closing a file is completed with either a success or an error.
   void OnCloseFileCompleted(
       int file_handle,
       const storage::AsyncFileUtil::StatusCallback& callback,
       base::File::Error result);
 
   scoped_ptr<ProvidedFileSystemInterface> file_system_;
   scoped_ptr<Queue> open_queue_;
 
   // Map from file handles to open queue tokens.
   std::map<int, int> opened_files_;
 
   base::WeakPtrFactory<ThrottledFileSystem> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(ThrottledFileSystem);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_THROTTLED_FILE_SYSTEM_H_