Experimental: Remove chromium shared timers

content/renderer/scheduler/renderer_task_queue_selector.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_task_queue_selector.h"
 
 #include "base/logging.h"
 #include "base/pending_task.h"
 #include "base/trace_event/trace_event_argument.h"
 
 namespace content {
 
-RendererTaskQueueSelector::RendererTaskQueueSelector() : starvation_count_(0) {
+RendererTaskQueueSelector::RendererTaskQueueSelector()
+    : starvation_count_(0), task_queue_selector_observer_(nullptr) {
 }
 
 RendererTaskQueueSelector::~RendererTaskQueueSelector() {
 }
 
 void RendererTaskQueueSelector::RegisterWorkQueues(
     const std::vector<const base::TaskQueue*>& work_queues) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   work_queues_ = work_queues;
   for (auto& queue_priority : queue_priorities_) {
     queue_priority.clear();
   }
 
   // By default, all work queues are set to normal priority.
   for (size_t i = 0; i < work_queues.size(); i++) {
     queue_priorities_[NORMAL_PRIORITY].insert(i);
   }
 }
 
 void RendererTaskQueueSelector::SetQueuePriority(size_t queue_index,
                                                  QueuePriority priority) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   DCHECK_LT(queue_index, work_queues_.size());
   DCHECK_LT(priority, QUEUE_PRIORITY_COUNT);
-  DisableQueue(queue_index);
+  bool previously_enabled = DisableQueue(queue_index);
   queue_priorities_[priority].insert(queue_index);
+  if (task_queue_selector_observer_ && !previously_enabled)
+    task_queue_selector_observer_->OnTaskQueueEnabled();
 }
 
 void RendererTaskQueueSelector::EnableQueue(size_t queue_index,
                                             QueuePriority priority) {
   SetQueuePriority(queue_index, priority);
 }
 
-void RendererTaskQueueSelector::DisableQueue(size_t queue_index) {
+bool RendererTaskQueueSelector::DisableQueue(size_t queue_index) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   DCHECK_LT(queue_index, work_queues_.size());
+  bool previously_enabled = false;
   for (auto& queue_priority : queue_priorities_) {
-    queue_priority.erase(queue_index);
+    if (queue_priority.erase(queue_index))
+      previously_enabled = true;
   }
+  return previously_enabled;
 }
 
 bool RendererTaskQueueSelector::IsQueueEnabled(size_t queue_index) const {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   DCHECK_LT(queue_index, work_queues_.size());
   for (const auto& queue_priority : queue_priorities_) {
     if (queue_priority.find(queue_index) != queue_priority.end())
       return true;
   }
   return false;
@@ skipping 104 matching lines @@
        priority < QUEUE_PRIORITY_COUNT; priority = NextPriority(priority)) {
     state->BeginArray(PriorityToString(priority));
     for (size_t queue_index : queue_priorities_[priority])
       state->AppendInteger(queue_index);
     state->EndArray();
   }
   state->EndDictionary();
   state->SetInteger("starvation_count", starvation_count_);
 }
 
+void RendererTaskQueueSelector::RegisterTaskQueueObserver(
+    TaskQueueSelectorObserver* observer) {
+  task_queue_selector_observer_ = observer;
+}
+
 }  // namespace content