Remove unused base/threading/worker_pool.h includes.

ios/web/net/crw_cert_verification_controller.mm

 // 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.
 
 #import "ios/web/net/crw_cert_verification_controller.h"
 
 #include <memory>
 
 #import "base/ios/block_types.h"
 #include "base/logging.h"
 #import "base/mac/bind_objc_block.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/task_scheduler/post_task.h"
-#include "base/threading/worker_pool.h"
 #include "ios/web/public/browser_state.h"
 #include "ios/web/public/certificate_policy_cache.h"
 #include "ios/web/public/web_thread.h"
 #import "ios/web/web_state/wk_web_view_security_util.h"
 #include "net/cert/cert_verify_proc_ios.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
@@ skipping 209 matching lines @@
 
   web::CertPolicy::Judgment judgment = _certPolicyCache->QueryPolicy(
       leafCert.get(), base::SysNSStringToUTF8(host), certStatus);
 
   return (judgment == web::CertPolicy::ALLOWED)
              ? web::CERT_ACCEPT_POLICY_RECOVERABLE_ERROR_ACCEPTED_BY_USER
              : web::CERT_ACCEPT_POLICY_RECOVERABLE_ERROR_UNDECIDED_BY_USER;
 }
 
 @end