Supervised users: Post blocking pool tasks with CONTINUE_SHUTDOWN behavior.

chrome/browser/supervised_user/supervised_user_service.cc

Index: chrome/browser/supervised_user/supervised_user_service.cc
diff --git a/chrome/browser/supervised_user/supervised_user_service.cc b/chrome/browser/supervised_user/supervised_user_service.cc
index b880731360fedb01d562f3bb284e1749243e35c7..d209811fa731f756400ec22a83eff43814ad9a66 100644
--- a/chrome/browser/supervised_user/supervised_user_service.cc
+++ b/chrome/browser/supervised_user/supervised_user_service.cc
@@ -623,7 +623,8 @@ void SupervisedUserService::OnSiteListUpdated() {
 void SupervisedUserService::LoadBlacklist(const base::FilePath& path,
                                           const GURL& url) {
   base::PostTaskAndReplyWithResult(
-      BrowserThread::GetBlockingPool(),
+      BrowserThread::GetBlockingPool()->GetTaskRunnerWithShutdownBehavior(
+          base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN).get(),
       FROM_HERE,
       base::Bind(&base::PathExists, path),
       base::Bind(&SupervisedUserService::OnBlacklistFileChecked,