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

chrome/browser/ui/app_list/app_list_test_util.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/ui/app_list/app_list_test_util.h"
 
 #include "base/files/file_path.h"
-#include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/common/chrome_constants.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension_set.h"
 
 const char AppListTestBase::kHostedAppId[] =
     "dceacbkfkmllgmjmbhgkpjegnodmildf";
 const char AppListTestBase::kPackagedApp1Id[] =
     "emfkafnhnpcmabnnkckkchdilgeoekbo";
 const char AppListTestBase::kPackagedApp2Id[] =
@@ skipping 23 matching lines @@
   service_->SetFileTaskRunnerForTesting(
       content::BrowserThread::GetBlockingPool()
           ->GetSequencedTaskRunnerWithShutdownBehavior(
               content::BrowserThread::GetBlockingPool()->GetNamedSequenceToken(
                   "ext_install-"),
               base::SequencedWorkerPool::SKIP_ON_SHUTDOWN));
 
   // There should be 4 extensions in the test profile.
   ASSERT_EQ(4U, registry()->enabled_extensions().size());
 }