TaskScheduler: Adjust shutdown behavior of delayed tasks.

base/task_scheduler/task.cc

Index: base/task_scheduler/task.cc
diff --git a/base/task_scheduler/task.cc b/base/task_scheduler/task.cc
index 8a589a202186dc2b3404c234e104a856ca57d8dd..baac443b2d9f20023d2adc7af72e2b52137960c5 100644
--- a/base/task_scheduler/task.cc
+++ b/base/task_scheduler/task.cc
@@ -9,13 +9,20 @@ namespace internal {
 
 Task::Task(const tracked_objects::Location& posted_from,
            const Closure& task,
-           const TaskTraits& traits,
+           const TaskTraits& traits_in,
            const TimeDelta& delay)
     : PendingTask(posted_from,
                   task,
                   delay.is_zero() ? TimeTicks() : TimeTicks::Now() + delay,
                   false),  // Not nestable.
-      traits(traits) {}
+      traits(traits_in) {
+  // Prevent a delayed BLOCK_SHUTDOWN task from blocking shutdown before being
+  // scheduled by changing its shutdown behavior to SKIP_ON_SHUTDOWN.
+  if (!delay.is_zero() &&

[danakj, 2016/10/03 20:08:45]

Maybe you could put this into a constexpr helper and keep the member as const.

+      traits.shutdown_behavior() == TaskShutdownBehavior::BLOCK_SHUTDOWN) {
+    traits.WithShutdownBehavior(TaskShutdownBehavior::SKIP_ON_SHUTDOWN);
+  }
+}
 
 Task::~Task() = default;