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

ios/chrome/browser/sync/ios_chrome_profile_sync_test_util.cc

Index: ios/chrome/browser/sync/ios_chrome_profile_sync_test_util.cc
diff --git a/ios/chrome/browser/sync/ios_chrome_profile_sync_test_util.cc b/ios/chrome/browser/sync/ios_chrome_profile_sync_test_util.cc
index e861a942c85098b8d380f2e66a6b5d53cd42e3ae..ef65725a1fc342e1dabfe2baa23f8a34317caec9 100644
--- a/ios/chrome/browser/sync/ios_chrome_profile_sync_test_util.cc
+++ b/ios/chrome/browser/sync/ios_chrome_profile_sync_test_util.cc
@@ -18,7 +18,6 @@
 #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(
@@ -40,11 +39,6 @@ CreateProfileSyncServiceParamsForTest(
   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;
 }