scheduler: Ensure consistent delayed task ordering between task queues

third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h

Index: third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
index 8381157e847d6e1ff1add54fc5fd4e34ebde8da5..3bdc5229f0e04dd1b85fa0c7203ed900fe94a11e 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
@@ -177,9 +177,12 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   }
 
   // Enqueues any delayed tasks which should be run now on the
-  // |delayed_work_queue|. Returns the deadline if a subsequent wakeup is
-  // required. Must be called from the main thread.
-  base::Optional<base::TimeTicks> WakeUpForDelayedWork(LazyNow* lazy_now);
+  // |delayed_work_queue|. Returns true and fills |out_next_wake_up_time| and
+  // |out_next_wake_up_sequence_num| if a subsequent wakeup is required. Must be
+  // called from the main thread.
+  bool WakeUpForDelayedWork(LazyNow* lazy_now,
+                            base::TimeTicks* out_next_wake_up_time,

[altimin, 2017/03/01 11:23:17]

Nit: time ticks and sequence number seem related. Can we group them in a struct
of sorts and return this new struct directly? It should make code more readable.

[Sami, 2017/03/01 12:17:42]

The other option I considered was to just return a pointer to the PendingTask,
but that seems like it's exposing too much information. Added a struct instead,
WDYT?

+                            int* out_next_wake_up_sequence_num);
 
   base::TimeTicks scheduled_time_domain_wakeup() const {
     return main_thread_only().scheduled_time_domain_wakeup;