[scheduler] Re-assign TODOs in FrameTaskQueueController and update comments

Change-Id: Ic6e7206b47f6bfa0c4d4451b2580acb95fe29ffb
Reviewed-on: https://chromium-review.googlesource.com/1187562Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Scott Haseley <shaseley@google.com>
Cr-Commit-Position: refs/heads/master@{#585838}

third_party/blink/renderer/platform/scheduler/main_thread/frame_task_queue_controller.cc

@@ -112,7 +112,10 @@ void FrameTaskQueueController::CreateNonLoadingTaskQueue(
               .SetQueueTraits(queue_traits)
               // Freeze when keep active is currently only set for the
               // throttleable queue.
-              // TODO(shaseley): Figure out how to set this for new queues.
+              // TODO(altimin): Figure out how to set this for new queues.
+              // Investigate which tasks must be kept alive, and if possible
+              // move them to an unfreezable queue and remove this override and
+              // the page scheduler KeepActive freezing override.
               .SetFreezeWhenKeepActive(queue_traits.can_be_throttled)
               .SetFrameScheduler(frame_scheduler_impl_));
   TaskQueueCreated(task_queue);

third_party/blink/renderer/platform/scheduler/main_thread/frame_task_queue_controller.h

@@ -106,8 +106,8 @@ class PLATFORM_EXPORT FrameTaskQueueController {
   void TaskQueueCreated(const scoped_refptr<MainThreadTaskQueue>&);
 
   // Map a set of QueueTraits to a QueueType.
-  // TODO(shaseley): Consider creating a new queue type kFrameNonLoading and use
-  // it instead of this for new queue types.
+  // TODO(crbug.com/877245): Consider creating a new queue type kFrameNonLoading
+  // and use it instead of this for new queue types.
   static MainThreadTaskQueue::QueueType QueueTypeFromQueueTraits(
       MainThreadTaskQueue::QueueTraits);