Revert of Remove header dependencies from sequence_checker.h to sequenced_worker_pool.h

chrome/browser/chromeos/arc/process/arc_process_service.cc

 // Copyright 2016 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.
 //
 // The main point of this class is to cache ARC proc nspid<->pid mapping
 // globally. Since the calculation is costly, a dedicated worker thread is
 // used. All read/write of its internal data structure (i.e., the mapping)
 // should be on this thread.
 
 #include "chrome/browser/chromeos/arc/process/arc_process_service.h"
 
 #include <algorithm>
 #include <queue>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
 #include <utility>
 
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/process/process.h"
 #include "base/process/process_iterator.h"
 #include "base/task_runner_util.h"
-#include "base/threading/sequenced_worker_pool.h"
 #include "base/trace_event/trace_event.h"
 #include "components/arc/arc_bridge_service.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace arc {
 
 using base::kNullProcessId;
 using base::Process;
 using base::ProcessId;
 using std::vector;
@@ skipping 245 matching lines @@
 void ArcProcessService::OnInstanceClosed() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   instance_ready_ = false;
 }
 
 inline ArcProcessService::NSPidToPidMap::NSPidToPidMap() {}
 
 inline ArcProcessService::NSPidToPidMap::~NSPidToPidMap() {}
 
 }  // namespace arc