Move throttling of background timers into the renderer scheduler

components/scheduler/base/time_domain.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_SCHEDULER_BASE_TIME_DOMAIN_H_
 #define COMPONENTS_SCHEDULER_BASE_TIME_DOMAIN_H_
 
 #include <map>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "components/scheduler/base/lazy_now.h"
 #include "components/scheduler/base/task_queue_impl.h"
 #include "components/scheduler/scheduler_export.h"
 
 namespace scheduler {
 namespace internal {
 class TaskQueueImpl;
 }  // internal
 class TaskQueueManager;
 class TaskQueueManagerDelegate;
 
-class SCHEDULER_EXPORT TimeDomain : public base::RefCounted<TimeDomain> {
+class SCHEDULER_EXPORT TimeDomain {
  public:
-  TimeDomain();
+  class SCHEDULER_EXPORT Observer {
+   public:
+    virtual ~Observer() {}
+
+    // Called when an empty TaskQueue registered with this TimeDomain has a task
+    // enqueued.
+    virtual void OnTimeDomainHasImmediateWork() = 0;
+
+    // Called when a TaskQueue registered with this TimeDomain has a delayed
+    // task enqueued and no other delayed tasks associated with this TimeDomain
+    // are pending.
+    virtual void OnTimeDomainHasDelayedWork() = 0;
+  };
+
+  explicit TimeDomain(Observer* observer);
+  virtual ~TimeDomain();
 
   // Returns a LazyNow that evaluate this TimeDomain's Now.  Can be called from
   // any thread.
   // TODO(alexclarke): Make this main thread only.
   virtual LazyNow CreateLazyNow() = 0;
 
   // Some TimeDomains support virtual time, this method tells us to advance time
   // if possible and return true if time was advanced.
   virtual bool MaybeAdvanceTime() = 0;
 
   // Returns the name of this time domain for tracing.
   virtual const char* GetName() const = 0;
 
   // If there is a scheduled delayed task, |out_time| is set to the scheduled
   // runtime for the next one and it returns true.  Returns false otherwise.
   bool NextScheduledRunTime(base::TimeTicks* out_time) const;
 
  protected:
   friend class internal::TaskQueueImpl;
   friend class TaskQueueManager;
-  friend class base::RefCounted<TimeDomain>;
-
-  virtual ~TimeDomain();
 
   void AsValueInto(base::trace_event::TracedValue* state) const;
 
   // Migrates |queue| from this time domain to |destination_time_domain|.
   void MigrateQueue(internal::TaskQueueImpl* queue,
                     TimeDomain* destination_time_domain);
 
   // If there is a scheduled delayed task, |out_task_queue| is set to the queue
   // the next task was posted to and it returns true.  Returns false otherwise.
   bool NextScheduledTaskQueue(TaskQueue** out_task_queue) const;
 
   // Adds |queue| to the set of task queues that UpdateWorkQueues calls
   // UpdateWorkQueue on.
   void RegisterAsUpdatableTaskQueue(internal::TaskQueueImpl* queue);
 
   // Schedules a call to TaskQueueImpl::MoveReadyDelayedTasksToIncomingQueue
   // when this TimeDomain reaches |delayed_run_time|.
   void ScheduleDelayedWork(internal::TaskQueueImpl* queue,
                            base::TimeTicks delayed_run_time,
                            LazyNow* lazy_now);
 
+  // Registers the |queue|.
+  void RegisterQueue(internal::TaskQueueImpl* queue);
+
   // Removes |queue| from the set of task queues that UpdateWorkQueues calls
   // UpdateWorkQueue on.
   void UnregisterAsUpdatableTaskQueue(internal::TaskQueueImpl* queue);
 
   // Removes |queue| from all internal data structures.
   void UnregisterQueue(internal::TaskQueueImpl* queue);
 
   // Updates active queues associated with this TimeDomain.
   void UpdateWorkQueues(bool should_trigger_wakeup,
                         const internal::TaskQueueImpl::Task* previous_task);
@@ skipping 25 matching lines @@
 
   // This lock guards only |newly_updatable_|.  It's not expected to be heavily
   // contended.
   base::Lock newly_updatable_lock_;
   std::vector<internal::TaskQueueImpl*> newly_updatable_;
 
   // Set of task queues with avaliable work on the incoming queue.  This should
   // only be accessed from the main thread.
   std::set<internal::TaskQueueImpl*> updatable_queue_set_;
 
+  std::set<internal::TaskQueueImpl*> registered_task_queues_;
+
+  Observer* observer_;
+
   base::ThreadChecker main_thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(TimeDomain);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_BASE_TIME_DOMAIN_H_