TaskScheduler: Always remove SchedulerWorker from idle stack on wake up.

base/task_scheduler/scheduler_worker_pool_impl.h

Index: base/task_scheduler/scheduler_worker_pool_impl.h
diff --git a/base/task_scheduler/scheduler_worker_pool_impl.h b/base/task_scheduler/scheduler_worker_pool_impl.h
index a621f797a53473b2096170a07689e456d5c3f2de..94998bc7a77bf1809af01bb217a86bbd6050eb4c 100644
--- a/base/task_scheduler/scheduler_worker_pool_impl.h
+++ b/base/task_scheduler/scheduler_worker_pool_impl.h
@@ -114,7 +114,11 @@ class BASE_EXPORT SchedulerWorkerPoolImpl : public SchedulerWorkerPool {
       size_t max_threads,
       const ReEnqueueSequenceCallback& re_enqueue_sequence_callback);
 
-  // Wakes up the last worker from this worker pool to go idle, if any.
+  // Wakes up |worker| and removes it from the idle stack.

[robliao, 2016/10/13 17:38:40]

Leave both of these comments like they were before. The idle stack is an
implementation detail.

Instead, I would discuss the invariant that the idle stack only contains idle
workers below.

[fdoray, 2016/10/13 18:46:55]

Done.

+  void WakeUpWorker(SchedulerWorker* worker);
+
+  // Wakes up and removes from the idle stack the last worker from this worker
+  // pool to go idle, if any.
   void WakeUpOneWorker();
 
   // Adds |worker| to |idle_workers_stack_|.