Remove after wakeup logic and replace PumpTask with Fences

third_party/WebKit/Source/platform/scheduler/child/idle_helper.h

Index: third_party/WebKit/Source/platform/scheduler/child/idle_helper.h
diff --git a/third_party/WebKit/Source/platform/scheduler/child/idle_helper.h b/third_party/WebKit/Source/platform/scheduler/child/idle_helper.h
index 47fc8cfb81f427731438994bfcf62dbd7d931edc..3b174818e4cd818d13d6b3f80389188905190487 100644
--- a/third_party/WebKit/Source/platform/scheduler/child/idle_helper.h
+++ b/third_party/WebKit/Source/platform/scheduler/child/idle_helper.h
@@ -18,7 +18,26 @@ namespace scheduler {
 
 class SchedulerHelper;
 
-// Common scheduler functionality for Idle tasks.
+// The job of the IdleHelper is to run idle tasks when the system is otherwise
+// idle. Idle tasks should be optional work, with no guarantee they will be run
+// at all. Idle tasks are subject to three levels of throttling:
+//
+//   1. Both idle queues are run a BEST_EFFORT priority (i.e. only selected if
+//      there is noting else to do.

[Sami, 2016/08/25 15:54:13]

typo: nothing

[alex clarke (OOO till 29th), 2016/08/26 13:29:08]

Done.

+//   2. The idle queues are only enabled during an idle period.
+//   3. Idle tasks posted from within an idle task run in the next idle period.
+//      This is achieved by posting DisableIdleTaskQueueTask or
+//      DisableNonNestableIdleTaskQueueTask before enabling the queues.
+//
+// There are two types of idle periods:
+//   1. Short idle period - typically less than 10ms run after begin main frame
+//      has finished, with the idle period ending at the compositor provided
+//      deadline.
+//   2. Long idle periods - typically more than 50ms when no frames are being

[Sami, 2016/08/25 15:54:13]

s/more than/up to/

[alex clarke (OOO till 29th), 2016/08/26 13:29:08]

Done.

+//      produced.
+//
+// Idle tasks are supplied a deadline, and should endeavor to finished before it
+// ends to avoid jank.
 class BLINK_PLATFORM_EXPORT IdleHelper
     : public base::MessageLoop::TaskObserver,
       public SingleThreadIdleTaskRunner::Delegate {
@@ -192,6 +211,9 @@ class BLINK_PLATFORM_EXPORT IdleHelper
                           base::TimeTicks new_deadline,
                           base::TimeTicks optional_now);
 
+  void DisableIdleTaskQueueTask();
+  void DisableNonNestableIdleTaskQueueTask();
+
   // Returns true if |state| represents being within an idle period state.
   static bool IsInIdlePeriod(IdlePeriodState state);
   // Returns true if |state| represents being within a long idle period state.
@@ -199,11 +221,20 @@ class BLINK_PLATFORM_EXPORT IdleHelper
 
   SchedulerHelper* helper_;  // NOT OWNED
   Delegate* delegate_;       // NOT OWNED
+
+  // We want to ensure idle tasks run in the next idle period. This necessitates
+  // two idle queues because we do this via posting a task to disable the queue
+  // and non-nestable tasks execution can be deferred, meaning we end up with
+  // the situation where we don't want any more nestable tasks to run but the
+  // non-nestable ones have yet to run.
   scoped_refptr<TaskQueue> idle_queue_;
+  scoped_refptr<TaskQueue> non_nestable_idle_queue_;
   scoped_refptr<SingleThreadIdleTaskRunner> idle_task_runner_;
 
   CancelableClosureHolder enable_next_long_idle_period_closure_;
   CancelableClosureHolder on_idle_task_posted_closure_;
+  CancelableClosureHolder disable_idle_queue_closure_;
+  CancelableClosureHolder disable_non_nestable_idle_queue_closure_;
 
   State state_;