Remove unused base/threading/worker_pool.h includes.

chrome/browser/chromeos/extensions/wallpaper_api.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/chromeos/extensions/wallpaper_api.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/strings/stringprintf.h"
-#include "base/threading/worker_pool.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/extensions/wallpaper_private_api.h"
 #include "chrome/browser/chromeos/file_manager/app_id.h"
 #include "chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/pref_names.h"
@@ skipping 250 matching lines @@
     const std::string& response) {
   if (success) {
     params_->details.data.reset(
         new std::vector<char>(response.begin(), response.end()));
     StartDecode(*params_->details.data);
   } else {
     SetError(response);
     SendResponse(false);
   }
 }