Move throttling of background timers into the renderer scheduler

components/scheduler/base/task_queue.h

Index: components/scheduler/base/task_queue.h
diff --git a/components/scheduler/base/task_queue.h b/components/scheduler/base/task_queue.h
index 393cc5077374a1b4f35302de9c1e6647b8273470..6c577b2f2d2e8e6d98c5701243bf1260700ec614 100644
--- a/components/scheduler/base/task_queue.h
+++ b/components/scheduler/base/task_queue.h
@@ -20,12 +20,6 @@ class SCHEDULER_EXPORT TaskQueue : public base::SingleThreadTaskRunner {
   // the TaskQueueManager's reference to it will be released soon.
   virtual void UnregisterTaskQueue() = 0;
 
-  // Post a delayed task at an absolute desired run time instead of a time
-  // delta from the current time.
-  virtual bool PostDelayedTaskAt(const tracked_objects::Location& from_here,
-                                 const base::Closure& task,
-                                 base::TimeTicks desired_run_time) = 0;
-
   enum QueuePriority {
     // Queues with control priority will run before any other queue, and will
     // explicitly starve other queues. Typically this should only be used for
@@ -145,11 +139,16 @@ class SCHEDULER_EXPORT TaskQueue : public base::SingleThreadTaskRunner {
   virtual bool IsQueueEnabled() const = 0;
 
   // Returns true if there no tasks in either the work or incoming task queue.
+  // This method ignores delayed tasks that are scheduled to run in the future.
   // Note that this function involves taking a lock, so calling it has some
   // overhead. NOTE this must be called on the thread this TaskQueue was created
   // by.
   virtual bool IsQueueEmpty() const;

[Sami, 2015/11/24 12:48:47]

Should we rename this to HasPendingImmediateTask to make the difference more
obvious?

[alex clarke (OOO till 29th), 2015/11/25 12:29:35]

Done.

 
+  // Returns true if there is one or more delayed tasks scheduled to run in the
+  // future. Can be called on any thread.
+  virtual bool HasPendingDelayedTask() const = 0;
+
   // Returns the QueueState. Note that this function involves taking a lock, so
   // calling it has some overhead.
   virtual QueueState GetQueueState() const = 0;