TaskScheduler: Add delayed run time to the constructor of Task.

base/task_scheduler/task.h

Index: base/task_scheduler/task.h
diff --git a/base/task_scheduler/task.h b/base/task_scheduler/task.h
index 6ac483d524916935e620f054001b07540131bb35..1f6ac4dc5572d436f2161df09b0ccd678199ddad 100644
--- a/base/task_scheduler/task.h
+++ b/base/task_scheduler/task.h
@@ -20,7 +20,8 @@ namespace internal {
 struct BASE_EXPORT Task : public PendingTask {
   Task(const tracked_objects::Location& posted_from,

[gab, 2016/04/18 16:20:39]

Also, I don't mind forcing the explicit parameter if you think that's better,
but given only one caller cares about providing this parameter I'd also be fine
with defining a delegated constructor (same as this one minus
|delayed_run_time|) which is delegated as:

Task(const tracked_objects::Location& posted_from, 
     const Closure& task,
     const TaskTraits& traits) 
    : Task(posted_from, task, traits, TimeTicks() {}

[fdoray, 2016/04/18 16:33:44]

I prefer forcing |delayed_run_time| because it is always provided when a Task is
constructed in production (I don't want to add a constructor that will only be
used by tests).

[gab, 2016/04/18 17:00:13]

Good point, hadn't realized all other uses were for tests.

        const Closure& task,
-       const TaskTraits& traits);
+       const TaskTraits& traits,
+       const TimeTicks& delayed_run_time);

[gab, 2016/04/18 16:12:14]

Document parameters (in particular is |delayed_run_time| a delay or the time at
which the delay expires).

[fdoray, 2016/04/18 16:33:44]

Done.

   ~Task();
 
   // The TaskTraits of this task.