[Reland] Optimize blink scheduler with an intrusive heap

third_party/WebKit/Source/platform/scheduler/base/work_queue.cc

 // Copyright 2015 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 "platform/scheduler/base/work_queue.h"
 
 #include "platform/scheduler/base/work_queue_sets.h"
 
 namespace blink {
 namespace scheduler {
 namespace internal {
 
 WorkQueue::WorkQueue(TaskQueueImpl* task_queue, const char* name)
     : work_queue_sets_(nullptr),
       task_queue_(task_queue),
       work_queue_set_index_(0),
+      heap_index_(0),
       name_(name),
       fence_(0) {}
 
 void WorkQueue::AsValueInto(base::trace_event::TracedValue* state) const {
   // Remove const to search |work_queue_| in the destructive manner. Restore the
   // content from |visited| later.
   std::queue<TaskQueueImpl::Task>* mutable_queue =
       const_cast<std::queue<TaskQueueImpl::Task>*>(&work_queue_);
   std::queue<TaskQueueImpl::Task> visited;
   while (!mutable_queue->empty()) {
@@ skipping 135 matching lines @@
   bool have_other_task =
       other_queue->GetFrontTaskEnqueueOrder(&other_enqueue_order);
   DCHECK(have_task);
   DCHECK(have_other_task);
   return enqueue_order < other_enqueue_order;
 }
 
 }  // namespace internal
 }  // namespace scheduler
 }  // namespace blink