Use TaskScheduler instead of blocking pool in supervised_user_blacklist.cc.

chrome/browser/supervised_user/experimental/supervised_user_blacklist.cc

Index: chrome/browser/supervised_user/experimental/supervised_user_blacklist.cc
diff --git a/chrome/browser/supervised_user/experimental/supervised_user_blacklist.cc b/chrome/browser/supervised_user/experimental/supervised_user_blacklist.cc
index a5163cc796f638a9196c3253c2936a471f4f8d84..4f401d2dc7bf14d44a7fea2d5a68c8d4904d021d 100644
--- a/chrome/browser/supervised_user/experimental/supervised_user_blacklist.cc
+++ b/chrome/browser/supervised_user/experimental/supervised_user_blacklist.cc
@@ -10,6 +10,7 @@
 
 #include "base/files/file_path.h"
 #include "base/files/memory_mapped_file.h"
+#include "base/task_scheduler/post_task.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "content/public/browser/browser_thread.h"
 #include "url/gurl.h"
@@ -20,8 +21,6 @@ namespace {
 
 std::unique_ptr<std::vector<SupervisedUserBlacklist::Hash>>
 ReadFromBinaryFileOnFileThread(const base::FilePath& path) {
-  DCHECK(BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
-
   std::unique_ptr<std::vector<SupervisedUserBlacklist::Hash>> host_hashes(
       new std::vector<SupervisedUserBlacklist::Hash>);
 
@@ -76,13 +75,16 @@ size_t SupervisedUserBlacklist::GetEntryCount() const {
 void SupervisedUserBlacklist::ReadFromFile(const base::FilePath& path,
                                            const base::Closure& done_callback) {
   base::PostTaskAndReplyWithResult(

[Bernhard Bauer, 2017/04/27 09:13:38]

Sorry, I thought I had replied here as well. Can you use
PostTaskWithTraitsAndReplyWithResult() here? And maybe replace base::Bind() with
base::BindOnce()? Thanks!

-      BrowserThread::GetBlockingPool()->GetTaskRunnerWithShutdownBehavior(
-          base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN).get(),
-      FROM_HERE,
-      base::Bind(&ReadFromBinaryFileOnFileThread, path),
+      base::CreateTaskRunnerWithTraits(
+          base::TaskTraits()
+              .MayBlock()
+              .WithPriority(base::TaskPriority::BACKGROUND)
+              .WithShutdownBehavior(
+                  base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN))
+          .get(),
+      FROM_HERE, base::Bind(&ReadFromBinaryFileOnFileThread, path),
       base::Bind(&SupervisedUserBlacklist::OnReadFromFileCompleted,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 done_callback));
+                 weak_ptr_factory_.GetWeakPtr(), done_callback));
 }
 
 void SupervisedUserBlacklist::OnReadFromFileCompleted(