Remove unused include in sequenced_worker_pool.h

chrome/service/service_utility_process_host.h

 // Copyright (c) 2012 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_SERVICE_SERVICE_UTILITY_PROCESS_HOST_H_
 #define CHROME_SERVICE_SERVICE_UTILITY_PROCESS_HOST_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "content/public/common/child_process_host_delegate.h"
 #include "ipc/ipc_platform_file.h"
 
 namespace base {
 class CommandLine;
 class File;
 class FilePath;
 class ScopedTempDir;
+class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace content {
 class ChildProcessHost;
 }
 
 namespace printing {
 class MetafilePlayer;
 class PdfRenderSettings;
 struct PageRange;
@@ skipping 123 matching lines @@
 
   class PdfToEmfState;
   std::unique_ptr<PdfToEmfState> pdf_to_emf_state_;
 
   base::WeakPtrFactory<ServiceUtilityProcessHost> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceUtilityProcessHost);
 };
 
 #endif  // CHROME_SERVICE_SERVICE_UTILITY_PROCESS_HOST_H_