Remove unused include in sequenced_worker_pool.h

content/child/fileapi/webfilewriter_impl.h

 // Copyright 2013 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 CONTENT_CHILD_FILEAPI_WEBFILEWRITER_IMPL_H_
 #define CONTENT_CHILD_FILEAPI_WEBFILEWRITER_IMPL_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "content/child/fileapi/webfilewriter_base.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace content {
 
 // An implementation of WebFileWriter for use in chrome renderers and workers.
 class WebFileWriterImpl : public WebFileWriterBase,
                           public base::SupportsWeakPtr<WebFileWriterImpl> {
  public:
   enum Type {
     TYPE_SYNC,
     TYPE_ASYNC,
   };
@@ skipping 18 matching lines @@
 
   void RunOnMainThread(const base::Closure& closure);
 
   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
   scoped_refptr<WriterBridge> bridge_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_FILEAPI_WEBFILEWRITER_IMPL_H_