Remove unused base/threading/worker_pool.h includes.

chrome/browser/extensions/api/image_writer_private/operation.cc

 // 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.
 
 #include "chrome/browser/extensions/api/image_writer_private/operation.h"
 
 #include <utility>
 
 #include "base/files/file_enumerator.h"
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
-#include "base/threading/worker_pool.h"
 #include "build/build_config.h"
 #include "chrome/browser/extensions/api/image_writer_private/error_messages.h"
 #include "chrome/browser/extensions/api/image_writer_private/operation_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "third_party/zlib/google/zip_reader.h"
 
 namespace extensions {
 namespace image_writer {
 
 using content::BrowserThread;
@@ skipping 332 matching lines @@
   for (std::vector<base::Closure>::iterator it = cleanup_functions_.begin();
        it != cleanup_functions_.end();
        ++it) {
     it->Run();
   }
   cleanup_functions_.clear();
 }
 
 }  // namespace image_writer
 }  // namespace extensions