Use TaskScheduler instead of SequencedWorkerPool in shell_url_request_context_getter.mm.

ios/web/shell/shell_url_request_context_getter.mm

 // Copyright 2014 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 "ios/web/shell/shell_url_request_context_getter.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/base_paths.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/path_service.h"
-#include "base/threading/sequenced_worker_pool.h"
+#include "base/task_scheduler/post_task.h"
 #import "ios/net/cookies/cookie_store_ios_persistent.h"
 #import "ios/web/public/web_client.h"
-#include "ios/web/public/web_thread.h"
 #include "ios/web/shell/shell_network_delegate.h"
 #include "net/base/cache_type.h"
 #include "net/cert/cert_verifier.h"
 #include "net/cert/ct_policy_enforcer.h"
 #include "net/cert/multi_log_ct_verifier.h"
 #include "net/dns/host_resolver.h"
 #include "net/extras/sqlite/sqlite_persistent_cookie_store.h"
 #include "net/http/http_auth_handler_factory.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_network_session.h"
@@ skipping 45 matching lines @@
         new net::URLRequestContextStorage(url_request_context_.get()));
 
     // Setup the cookie store.
     base::FilePath cookie_path;
     bool cookie_path_found = PathService::Get(base::DIR_APP_DATA, &cookie_path);
     DCHECK(cookie_path_found);
     cookie_path = cookie_path.Append("WebShell").Append("Cookies");
     scoped_refptr<net::CookieMonster::PersistentCookieStore> persistent_store =
         new net::SQLitePersistentCookieStore(
             cookie_path, network_task_runner_,
-            web::WebThread::GetBlockingPool()->GetSequencedTaskRunner(
-                web::WebThread::GetBlockingPool()->GetSequenceToken()),
+            base::CreateSequencedTaskRunnerWithTraits(
+                {base::MayBlock(), base::TaskPriority::BACKGROUND}),
             true, nullptr);
     std::unique_ptr<net::CookieStoreIOS> cookie_store(
         new net::CookieStoreIOSPersistent(persistent_store.get()));
     storage_->set_cookie_store(std::move(cookie_store));
 
     std::string user_agent =
         web::GetWebClient()->GetUserAgent(web::UserAgentType::MOBILE);
     storage_->set_http_user_agent_settings(
         base::MakeUnique<net::StaticHttpUserAgentSettings>("en-us,en",
                                                            user_agent));
@@ skipping 71 matching lines @@
 
   return url_request_context_.get();
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 ShellURLRequestContextGetter::GetNetworkTaskRunner() const {
   return network_task_runner_;
 }
 
 }  // namespace web