Remove unused include in sequenced_worker_pool.h

third_party/WebKit/Source/platform/WebTaskRunner.cpp

 // Copyright 2015 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 "public/platform/WebTaskRunner.h"
 
+#include "base/single_thread_task_runner.h"
+
 namespace blink {
 
 // This class holds a reference to a TaskHandle to keep it alive while a task is
 // pending in a task queue, and clears the reference on the task disposal, so
 // that it doesn't leave a circular reference like below:
 //   struct Foo : GarbageCollected<Foo> {
 //     void bar() {}
 //     RefPtr<TaskHandle> m_handle;
 //   };
 //
@@ skipping 94 matching lines @@
   DCHECK(runsTasksOnCurrentThread());
   RefPtr<TaskHandle> handle = adoptRef(new TaskHandle(std::move(task)));
   postDelayedTask(location,
                   WTF::bind(&TaskHandle::run, handle->asWeakPtr(),
                             TaskHandle::CancelOnTaskDestruction(handle)),
                   delayMs);
   return handle;
 }
 
 }  // namespace blink