[Try # 3] Scheduler refactoring to virtually eliminate redundant DoWorks

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 6f85115a9f73d05b35a6f9a4ed51a3847c7d5c24..4ec3b61ad821c6c22c44f5447c1bfa44c071036e 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
@@ -140,9 +140,16 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   const char* GetName() const override;
   QueueType GetQueueType() const override;
 
-  // If this returns false then future updates for this queue are not needed
-  // unless requested.
-  bool MaybeUpdateImmediateWorkQueues();
+  // Returns true if a posted immediate task could run (i.e. the queue is
+  // enabled and not blocked by a fence). Must only be called from the thread
+  // this task queue was created on
+  bool ImmediateTaskCouldRun() const;
+
+  // Returns the current queue of immediate incoming tasks.
+  WTF::Deque<TaskQueueImpl::Task> TakeImmediateIncomingQueue();
+
+  // Must only be called from the thread this task queue was created on.
+  void ReloadImmediateWorkQueueIfEmpty();
 
   void AsValueInto(base::trace_event::TracedValue* state) const;
 
@@ -173,9 +180,9 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   }
 
   // Enqueues any delayed tasks which should be run now on the
-  // |delayed_work_queue|. It also schedules the next wake up with the
-  // TimeDomain. Must be called from the main thread.
-  void WakeUpForDelayedWork(LazyNow* lazy_now);
+  // |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);
 
   base::TimeTicks scheduled_time_domain_wakeup() const {
     return main_thread_only().scheduled_time_domain_wakeup;
@@ -193,6 +200,7 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
     main_thread_only().heap_handle = heap_handle;
   }
 
+  void PushImmediateIncomingTaskForTest(TaskQueueImpl::Task&& task);
   EnqueueOrder GetFenceForTest() const;
 
   class QueueEnabledVoterImpl : public QueueEnabledVoter {
@@ -294,9 +302,6 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
       EnqueueOrder sequence_number,
       bool nestable);
 
-  // As BlockedByFence but safe to be called while locked.
-  bool BlockedByFenceLocked() const;
-
   void TraceQueueSize(bool is_locked) const;
   static void QueueAsValueInto(const WTF::Deque<Task>& queue,
                                base::trace_event::TracedValue* state);
@@ -323,9 +328,9 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   }
 
   const QueueType type_;
-  const char* name_;
-  const char* disabled_by_default_tracing_category_;
-  const char* disabled_by_default_verbose_tracing_category_;
+  const char* const name_;
+  const char* const disabled_by_default_tracing_category_;
+  const char* const disabled_by_default_verbose_tracing_category_;
 
   base::ThreadChecker main_thread_checker_;
   MainThreadOnly main_thread_only_;