[SyncFS] Remove unneeded #include from sync_task_manager.h

chrome/browser/sync_file_system/drive_backend/sync_task_manager.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 "chrome/browser/sync_file_system/drive_backend/sync_task_manager.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/memory/scoped_ptr.h"
+#include "chrome/browser/sync_file_system/drive_backend/sync_task.h"
 #include "chrome/browser/sync_file_system/drive_backend/sync_task_token.h"
 #include "chrome/browser/sync_file_system/sync_file_metadata.h"
 
 using fileapi::FileSystemURL;
 
 namespace sync_file_system {
 namespace drive_backend {
 
 namespace {
 
@@ skipping 352 matching lines @@
     closure.Run();
     return;
   }
 
   if (client_)
     client_->MaybeScheduleNextTask();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system