Fix TimeDomain::MigrateQueue with incoming immediate tasks

components/scheduler/base/task_queue_manager_unittest.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 "components/scheduler/base/task_queue_manager.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 1609 matching lines @@
 
   test_task_runner_->RunUntilIdle();
   EXPECT_THAT(run_order, ElementsAre(1, 2, 3, 4));
 
   runners_[0]->UnregisterTaskQueue();
 
   manager_->UnregisterTimeDomain(domain_a.get());
   manager_->UnregisterTimeDomain(domain_b.get());
 }
 
+TEST_F(TaskQueueManagerTest, TimeDomainMigrationWithIncomingImmediateTasks) {
+  Initialize(1u);
+
+  base::TimeTicks start_time = manager_->delegate()->NowTicks();
+  std::unique_ptr<VirtualTimeDomain> domain_a(
+      new VirtualTimeDomain(nullptr, start_time));
+  std::unique_ptr<VirtualTimeDomain> domain_b(
+      new VirtualTimeDomain(nullptr, start_time));
+  manager_->RegisterTimeDomain(domain_a.get());
+  manager_->RegisterTimeDomain(domain_b.get());
+
+  runners_[0]->SetTimeDomain(domain_a.get());
+  std::vector<EnqueueOrder> run_order;
+  runners_[0]->PostTask(FROM_HERE, base::Bind(&TestTask, 1, &run_order));
+  runners_[0]->SetTimeDomain(domain_b.get());
+
+  test_task_runner_->RunUntilIdle();
+  EXPECT_THAT(run_order, ElementsAre(1));
+
+  runners_[0]->UnregisterTaskQueue();
+
+  manager_->UnregisterTimeDomain(domain_a.get());
+  manager_->UnregisterTimeDomain(domain_b.get());
+}
+
 namespace {
 void ChromiumRunloopInspectionTask(
     scoped_refptr<cc::OrderedSimpleTaskRunner> test_task_runner) {
   EXPECT_EQ(1u, test_task_runner->NumPendingTasks());
 }
 }  // namespace
 
 TEST_F(TaskQueueManagerTest, NumberOfPendingTasksOnChromiumRunLoop) {
   Initialize(1u);
 
@@ skipping 334 matching lines @@
 
   trace_analyzer::TraceEventVector events;
   Query q = Query::EventPhaseIs(TRACE_EVENT_PHASE_ENTER_CONTEXT) ||
             Query::EventPhaseIs(TRACE_EVENT_PHASE_LEAVE_CONTEXT);
   analyzer->FindEvents(q, &events);
 
   EXPECT_EQ(2u, events.size());
 }
 
 }  // namespace scheduler