scheduler: Implement task observers

content/renderer/scheduler/renderer_scheduler_impl.cc

 // Copyright 2014 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.
 
 #include "content/renderer/scheduler/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
@@ skipping 30 matching lines @@
       &RendererSchedulerImpl::EndIdlePeriod, weak_renderer_scheduler_ptr_));
   idle_task_runner_ = make_scoped_refptr(new SingleThreadIdleTaskRunner(
       task_queue_manager_->TaskRunnerForQueue(IDLE_TASK_QUEUE),
       base::Bind(&RendererSchedulerImpl::CurrentIdleTaskDeadlineCallback,
                  weak_renderer_scheduler_ptr_)));
   renderer_task_queue_selector_->SetQueuePriority(
       CONTROL_TASK_QUEUE, RendererTaskQueueSelector::CONTROL_PRIORITY);
   renderer_task_queue_selector_->DisableQueue(IDLE_TASK_QUEUE);
   task_queue_manager_->SetAutoPump(IDLE_TASK_QUEUE, false);
   // TODO(skyostil): Increase this to 4 (crbug.com/444764).
-  task_queue_manager_->SetWorkBatchSize(1);
+  task_queue_manager_->SetWorkBatchSize(4);

[rmcilroy, 2015/02/13 16:14:00]

Let's do this in a different patch (just in case we need to revert it again, at
least it will be easier to re-land).  Also remove the TODO above when you
actually do this.

[Sami, 2015/02/13 16:22:34]

Oops, I wasn't actually meaning to do it here. My bad, thanks for spotting.

 
   for (size_t i = 0; i < TASK_QUEUE_COUNT; i++) {
     task_queue_manager_->SetQueueName(
         i, TaskQueueIdToString(static_cast<QueueId>(i)));
   }
   TRACE_EVENT_OBJECT_CREATED_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"), "RendererScheduler",
       this);
 }
 
@@ skipping 377 matching lines @@
       // With no observable effect, these meta events do not indicate a
       // meaningful touchstart response and should not impact task priority.
       return current_state;
 
     default:
       break;
   }
   return INPUT_ACTIVE;
 }
 
+void RendererSchedulerImpl::AddTaskObserver(
+    base::MessageLoop::TaskObserver* task_observer) {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  task_queue_manager_->AddTaskObserver(task_observer);
+}
+
+void RendererSchedulerImpl::RemoveTaskObserver(
+    base::MessageLoop::TaskObserver* task_observer) {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  task_queue_manager_->RemoveTaskObserver(task_observer);
+}
+
 }  // namespace content