Change SchedulerWorker::ShouldExit Checks Ordering

base/task_scheduler/scheduler_worker.cc

Index: base/task_scheduler/scheduler_worker.cc
diff --git a/base/task_scheduler/scheduler_worker.cc b/base/task_scheduler/scheduler_worker.cc
index ec7ff0e3cc75a7505429e7d1dc18509d8695aefc..4084c527a73c17e6ba4fa80398e792b1c268566b 100644
--- a/base/task_scheduler/scheduler_worker.cc
+++ b/base/task_scheduler/scheduler_worker.cc
@@ -331,8 +331,12 @@ void SchedulerWorker::CreateThreadAssertSynchronized() {
 }
 
 bool SchedulerWorker::ShouldExit() {
-  return task_tracker_->IsShutdownComplete() ||
-         join_called_for_testing_.IsSet() || should_exit_.IsSet();
+  // The ordering of the checks is important below. This SchedulerWorker may be
+  // released and outlive |task_tracker_| in unit tests. However, when the
+  // SchedulerWorker is released, |should_exit_| will be set, so check that
+  // first.
+  return should_exit_.IsSet() || join_called_for_testing_.IsSet() ||
+         task_tracker_->IsShutdownComplete();
 }
 
 }  // namespace internal