Remove unused include in sequenced_worker_pool.h

ipc/attachment_broker_privileged.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 IPC_ATTACHMENT_BROKER_PRIVILEGED_H_
 #define IPC_ATTACHMENT_BROKER_PRIVILEGED_H_
 
 #include <utility>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/single_thread_task_runner.h"
 #include "build/build_config.h"
 #include "ipc/attachment_broker.h"
 #include "ipc/ipc_export.h"
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 namespace base {
 class PortProvider;
 }  // namespace base
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
@@ skipping 98 matching lines @@
  private:
   // A vector of Endpoints, and the SingleThreadTaskRunner that should be used
   // to invoke Send() on each Endpoint.
   std::vector<EndpointRunnerPair> endpoints_;
   DISALLOW_COPY_AND_ASSIGN(AttachmentBrokerPrivileged);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_ATTACHMENT_BROKER_PRIVILEGED_H_