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

chrome/browser/ui/webui/chromeos/image_source.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/webui/chromeos/image_source.h"
 
 #include <stddef.h>
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner_util.h"
+#include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/chromeos/login/users/avatar/user_image_loader.h"
 #include "chrome/common/url_constants.h"
 #include "components/user_manager/user_image/user_image.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/mime_util.h"
 
 using content::BrowserThread;
 
 namespace chromeos {
@@ skipping 87 matching lines @@
     return false;
 
   for (size_t i = 0; i < arraysize(kWhitelistedDirectories); i++) {
     if (components[0] == kWhitelistedDirectories[i])
       return true;
   }
   return false;
 }
 
 }  // namespace chromeos