Remove unused include in sequenced_worker_pool.h

components/drive/chromeos/file_system/get_file_for_saving_operation.h

 // Copyright 2013 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_DRIVE_CHROMEOS_FILE_SYSTEM_GET_FILE_FOR_SAVING_OPERATION_H_
 #define COMPONENTS_DRIVE_CHROMEOS_FILE_SYSTEM_GET_FILE_FOR_SAVING_OPERATION_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "components/drive/chromeos/file_system_interface.h"
 #include "components/drive/file_errors.h"
 
 namespace base {
 class FilePath;
 class ScopedClosureRunner;
 class SequencedTaskRunner;
+class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace drive {
 namespace internal {
 class FileCache;
 class FileWriteWatcher;
 class ResourceMetadata;
 }  // namespace internal
 
 class EventLogger;
@@ skipping 70 matching lines @@
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate the weak pointers before any other members are destroyed.
   base::WeakPtrFactory<GetFileForSavingOperation> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(GetFileForSavingOperation);
 };
 
 }  // namespace file_system
 }  // namespace drive
 
 #endif  // COMPONENTS_DRIVE_CHROMEOS_FILE_SYSTEM_GET_FILE_FOR_SAVING_OPERATION_H_