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

chrome/test/chromedriver/net/sync_websocket_impl.h

 // 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.
 
 #ifndef CHROME_TEST_CHROMEDRIVER_NET_SYNC_WEBSOCKET_IMPL_H_
 #define CHROME_TEST_CHROMEDRIVER_NET_SYNC_WEBSOCKET_IMPL_H_
 
 #include <list>
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner_helpers.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "chrome/test/chromedriver/net/sync_websocket.h"
 #include "chrome/test/chromedriver/net/websocket.h"
 #include "net/base/completion_callback.h"
 
 namespace base {
 class WaitableEvent;
 }
 
@@ skipping 76 matching lines @@
   scoped_refptr<Core> core_;
 };
 
 struct SyncWebSocketImpl::CoreTraits {
   static void Destruct(const SyncWebSocketImpl::Core* core) {
     core->OnDestruct();
   }
 };
 
 #endif  // CHROME_TEST_CHROMEDRIVER_NET_SYNC_WEBSOCKET_IMPL_H_