[Sync] ModelTypeStore factory shouldn't require valid PSS to function correctly

ios/chrome/browser/sync/ios_chrome_profile_sync_test_util.cc

 // 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.
 
 #include "ios/chrome/browser/sync/ios_chrome_profile_sync_test_util.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "components/browser_sync/profile_sync_service_mock.h"
 #include "components/browser_sync/profile_sync_test_util.h"
 #include "components/signin/core/browser/profile_oauth2_token_service.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "components/sync/driver/signin_manager_wrapper.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/signin/oauth2_token_service_factory.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
 #include "ios/chrome/browser/sync/ios_chrome_sync_client.h"
 #include "ios/chrome/common/channel_info.h"
-#include "ios/web/public/web_thread.h"
 
 browser_sync::ProfileSyncService::InitParams
 CreateProfileSyncServiceParamsForTest(
     std::unique_ptr<syncer::SyncClient> sync_client,
     ios::ChromeBrowserState* browser_state) {
   browser_sync::ProfileSyncService::InitParams init_params;
 
   init_params.signin_wrapper = base::MakeUnique<SigninManagerWrapper>(
       ios::SigninManagerFactory::GetForBrowserState(browser_state));
   init_params.oauth2_token_service =
       OAuth2TokenServiceFactory::GetForBrowserState(browser_state);
   init_params.start_behavior = browser_sync::ProfileSyncService::MANUAL_START;
   init_params.sync_client =
       sync_client ? std::move(sync_client)
                   : base::MakeUnique<IOSChromeSyncClient>(browser_state);
   init_params.network_time_update_callback =
       base::Bind(&browser_sync::EmptyNetworkTimeUpdate);
   init_params.base_directory = browser_state->GetStatePath();
   init_params.url_request_context = browser_state->GetRequestContext();
   init_params.debug_identifier = browser_state->GetDebugName();
   init_params.channel = ::GetChannel();
-  base::SequencedWorkerPool* blocking_pool = web::WebThread::GetBlockingPool();
-  init_params.blocking_task_runner =
-      blocking_pool->GetSequencedTaskRunnerWithShutdownBehavior(
-          blocking_pool->GetSequenceToken(),
-          base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
 
   return init_params;
 }
 
 std::unique_ptr<KeyedService> BuildMockProfileSyncService(
     web::BrowserState* context) {
   return base::MakeUnique<browser_sync::ProfileSyncServiceMock>(
       CreateProfileSyncServiceParamsForTest(
           nullptr, ios::ChromeBrowserState::FromBrowserState(context)));
 }