Add missing #include around sequenced_worker_pool.h in //chrome

chrome/browser/captive_portal/captive_portal_browsertest.cc

 // 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.
 
 #include <map>
 #include <memory>
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/sequenced_worker_pool.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "chrome/browser/captive_portal/captive_portal_service.h"
 #include "chrome/browser/captive_portal/captive_portal_service_factory.h"
 #include "chrome/browser/captive_portal/captive_portal_tab_helper.h"
 #include "chrome/browser/captive_portal/captive_portal_tab_reloader.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/net/url_request_mock_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ssl/captive_portal_blocking_page.h"
@@ skipping 2809 matching lines @@
 
   EXPECT_EQ(CaptivePortalTabReloader::STATE_NEEDS_RELOAD,
             GetStateOfTabReloaderAt(browser(), broken_tab_index));
 
   WaitForInterstitialAttach(broken_tab_contents);
   portal_observer.WaitForResults(1);
 
   EXPECT_EQ(SSLBlockingPage::kTypeForTesting,
             GetInterstitialType(broken_tab_contents));
 }