scheduler: Maintain a constant enqueue order for every task

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

Index: third_party/WebKit/Source/platform/scheduler/base/task_queue_selector_unittest.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_selector_unittest.cc b/third_party/WebKit/Source/platform/scheduler/base/task_queue_selector_unittest.cc
index 08c5b0d050bc18606fde0429ea3d45e5330f1f7f..c4111db8e305af39d4fa0cd68f0f5c0503cea688 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_selector_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_selector_unittest.cc
@@ -66,8 +66,8 @@ class TaskQueueSelectorTest : public testing::Test {
     for (size_t i = 0; i < num_tasks; i++) {
       changed_queue_set.insert(queue_indices[i]);
       task_queues_[queue_indices[i]]->immediate_work_queue()->Push(
-          TaskQueueImpl::Task(FROM_HERE, test_closure_, base::TimeTicks(), 0,
-                              true, i));
+          TaskQueueImpl::Task(FROM_HERE, test_closure_, {base::TimeTicks(), i},
+                              true));
     }
   }
 
@@ -78,8 +78,8 @@ class TaskQueueSelectorTest : public testing::Test {
     for (size_t i = 0; i < num_tasks; i++) {
       changed_queue_set.insert(queue_indices[i]);
       task_queues_[queue_indices[i]]->immediate_work_queue()->Push(
-          TaskQueueImpl::Task(FROM_HERE, test_closure_, base::TimeTicks(), 0,
-                              true, enqueue_orders[i]));
+          TaskQueueImpl::Task(FROM_HERE, test_closure_,
+                              {base::TimeTicks(), enqueue_orders[i]}, true));
     }
   }
 
@@ -378,8 +378,8 @@ TEST_F(TaskQueueSelectorTest, ChooseOldestWithPriority_Empty) {
 }
 
 TEST_F(TaskQueueSelectorTest, ChooseOldestWithPriority_OnlyDelayed) {
-  task_queues_[0]->delayed_work_queue()->Push(TaskQueueImpl::Task(
-      FROM_HERE, test_closure_, base::TimeTicks(), 0, true, 0));
+  task_queues_[0]->delayed_work_queue()->Push(
+      TaskQueueImpl::Task(FROM_HERE, test_closure_, EnqueueOrder(), true));
 
   WorkQueue* chosen_work_queue = nullptr;
   bool chose_delayed_over_immediate = false;
@@ -391,8 +391,8 @@ TEST_F(TaskQueueSelectorTest, ChooseOldestWithPriority_OnlyDelayed) {
 }
 
 TEST_F(TaskQueueSelectorTest, ChooseOldestWithPriority_OnlyImmediate) {
-  task_queues_[0]->immediate_work_queue()->Push(TaskQueueImpl::Task(
-      FROM_HERE, test_closure_, base::TimeTicks(), 0, true, 0));
+  task_queues_[0]->immediate_work_queue()->Push(
+      TaskQueueImpl::Task(FROM_HERE, test_closure_, EnqueueOrder(), true));
 
   WorkQueue* chosen_work_queue = nullptr;
   bool chose_delayed_over_immediate = false;
@@ -418,9 +418,7 @@ TEST_F(TaskQueueSelectorTest, TestObserverWithOneBlockedQueue) {
   voter->SetQueueEnabled(false);
   selector.DisableQueue(task_queue.get());
 
-  TaskQueueImpl::Task task(FROM_HERE, test_closure_, base::TimeTicks(), 0,
-                           true);
-  task.set_enqueue_order(0);
+  TaskQueueImpl::Task task(FROM_HERE, test_closure_, EnqueueOrder(), true);
   task_queue->immediate_work_queue()->Push(std::move(task));
 
   WorkQueue* chosen_work_queue;
@@ -454,12 +452,9 @@ TEST_F(TaskQueueSelectorTest, TestObserverWithTwoBlockedQueues) {
 
   selector.SetQueuePriority(task_queue2.get(), TaskQueue::CONTROL_PRIORITY);
 
-  TaskQueueImpl::Task task1(FROM_HERE, test_closure_, base::TimeTicks(), 0,
-                            true);
-  TaskQueueImpl::Task task2(FROM_HERE, test_closure_, base::TimeTicks(), 1,
+  TaskQueueImpl::Task task1(FROM_HERE, test_closure_, EnqueueOrder(), true);
+  TaskQueueImpl::Task task2(FROM_HERE, test_closure_, {base::TimeTicks(), 1},
                             true);
-  task1.set_enqueue_order(0);
-  task2.set_enqueue_order(1);
   task_queue->immediate_work_queue()->Push(std::move(task1));
   task_queue2->immediate_work_queue()->Push(std::move(task2));
 
@@ -508,15 +503,13 @@ class ChooseOldestWithPriorityTest
       public testing::WithParamInterface<ChooseOldestWithPriorityTestParam> {};
 
 TEST_P(ChooseOldestWithPriorityTest, RoundRobinTest) {
-  task_queues_[0]->immediate_work_queue()->Push(
-      TaskQueueImpl::Task(FROM_HERE, test_closure_, base::TimeTicks(),
-                          GetParam().immediate_task_enqueue_order, true,
-                          GetParam().immediate_task_enqueue_order));
+  task_queues_[0]->immediate_work_queue()->Push(TaskQueueImpl::Task(
+      FROM_HERE, test_closure_,
+      {base::TimeTicks(), GetParam().immediate_task_enqueue_order}, true));
 
-  task_queues_[0]->delayed_work_queue()->Push(
-      TaskQueueImpl::Task(FROM_HERE, test_closure_, base::TimeTicks(),
-                          GetParam().delayed_task_enqueue_order, true,
-                          GetParam().delayed_task_enqueue_order));
+  task_queues_[0]->delayed_work_queue()->Push(TaskQueueImpl::Task(
+      FROM_HERE, test_closure_,
+      {base::TimeTicks(), GetParam().delayed_task_enqueue_order}, true));
 
   selector_.SetImmediateStarvationCountForTest(
       GetParam().immediate_starvation_count);