Revert of scheduler: Implement task observers

content/renderer/scheduler/task_queue_manager.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/task_queue_manager.h"
 
 #include <queue>
 
 #include "base/bind.h"
-#include "base/observer_list.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/test/test_now_source.h"
 #include "content/renderer/scheduler/task_queue_selector.h"
 
 namespace {
 const int64_t kMaxTimeTicks = std::numeric_limits<int64>::max();
 }
 
 namespace content {
@@ skipping 386 matching lines @@
 void TaskQueueManager::ProcessTaskFromWorkQueue(size_t queue_index) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   internal::TaskQueue* queue = Queue(queue_index);
   base::PendingTask pending_task = queue->TakeTaskFromWorkQueue();
   if (!pending_task.nestable) {
     // Defer non-nestable work to the main task runner.  NOTE these tasks can be
     // arbitrarily delayed so the additional delay should not be a problem.
     main_task_runner_->PostNonNestableTask(pending_task.posted_from,
                                            pending_task.task);
   } else {
-    FOR_EACH_OBSERVER(base::MessageLoop::TaskObserver, task_observers_,
-                      WillProcessTask(pending_task));
     task_annotator_.RunTask("TaskQueueManager::PostTask",
                             "TaskQueueManager::RunTask", pending_task);
-    FOR_EACH_OBSERVER(base::MessageLoop::TaskObserver, task_observers_,
-                      DidProcessTask(pending_task));
   }
 }
 
 bool TaskQueueManager::RunsTasksOnCurrentThread() const {
   return main_task_runner_->RunsTasksOnCurrentThread();
 }
 
 bool TaskQueueManager::PostDelayedTask(
     const tracked_objects::Location& from_here,
     const base::Closure& task,
     base::TimeDelta delay) {
   DCHECK(delay > base::TimeDelta());
   return main_task_runner_->PostDelayedTask(from_here, task, delay);
 }
 
 void TaskQueueManager::SetQueueName(size_t queue_index, const char* name) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   internal::TaskQueue* queue = Queue(queue_index);
   queue->set_name(name);
 }
 
 void TaskQueueManager::SetWorkBatchSize(int work_batch_size) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   DCHECK_GE(work_batch_size, 1);
   work_batch_size_ = work_batch_size;
 }
 
-void TaskQueueManager::AddTaskObserver(
-    base::MessageLoop::TaskObserver* task_observer) {
-  DCHECK(main_thread_checker_.CalledOnValidThread());
-  task_observers_.AddObserver(task_observer);
-}
-
-void TaskQueueManager::RemoveTaskObserver(
-    base::MessageLoop::TaskObserver* task_observer) {
-  DCHECK(main_thread_checker_.CalledOnValidThread());
-  task_observers_.RemoveObserver(task_observer);
-}
-
 void TaskQueueManager::SetTimeSourceForTesting(
     scoped_refptr<cc::TestNowSource> time_source) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   time_source_ = time_source;
 }
 
 base::TimeTicks TaskQueueManager::Now() const {
   return UNLIKELY(time_source_) ? time_source_->Now() : base::TimeTicks::Now();
 }
 
 scoped_refptr<base::trace_event::ConvertableToTraceFormat>
 TaskQueueManager::AsValueWithSelectorResult(bool should_run,
                                             size_t selected_queue) const {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   scoped_refptr<base::trace_event::TracedValue> state =
       new base::trace_event::TracedValue();
   state->BeginArray("queues");
   for (auto& queue : queues_)
     queue->AsValueInto(state.get());
   state->EndArray();
   state->BeginDictionary("selector");
   selector_->AsValueInto(state.get());
   state->EndDictionary();
   if (should_run)
     state->SetInteger("selected_queue", selected_queue);
   return state;
 }
 
 }  // namespace content