Report expected task queueing time via UMA

components/scheduler/renderer/auto_advancing_virtual_time_domain_unittest.cc

 // Copyright 2016 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/renderer/auto_advancing_virtual_time_domain.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
 #include "components/scheduler/base/task_queue_manager.h"
+#include "components/scheduler/base/test_task_time_tracker.h"
 #include "components/scheduler/base/test_time_source.h"
 #include "components/scheduler/child/scheduler_tqm_delegate_for_test.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace scheduler {
 
 class AutoAdvancingVirtualTimeDomainTest : public testing::Test {
  public:
   AutoAdvancingVirtualTimeDomainTest() {}
   ~AutoAdvancingVirtualTimeDomainTest() override {}
 
   void SetUp() override {
     clock_.reset(new base::SimpleTestTickClock());
     clock_->Advance(base::TimeDelta::FromMicroseconds(5000));
 
     test_time_source_.reset(new TestTimeSource(clock_.get()));
     mock_task_runner_ = make_scoped_refptr(
         new cc::OrderedSimpleTaskRunner(clock_.get(), false));
     main_task_runner_ = SchedulerTqmDelegateForTest::Create(
         mock_task_runner_, base::WrapUnique(new TestTimeSource(clock_.get())));
-    manager_ = base::WrapUnique(
-        new TaskQueueManager(main_task_runner_, "test.scheduler",
-                             "test.scheduler", "test.scheduler.debug"));
+
+    manager_ = base::WrapUnique(new TaskQueueManager(
+        main_task_runner_, "test.scheduler", "test.scheduler",
+        "test.scheduler.debug"));
+    manager_->SetTaskTimeTracker(&test_task_time_tracker_);
     task_runner_ =
         manager_->NewTaskQueue(TaskQueue::Spec("test_task_queue"));
     initial_time_= clock_->NowTicks();
     auto_advancing_time_domain_.reset(
         new AutoAdvancingVirtualTimeDomain(initial_time_));
     manager_->RegisterTimeDomain(auto_advancing_time_domain_.get());
     task_runner_->SetTimeDomain(auto_advancing_time_domain_.get());
   }
 
   void TearDown() override {
     task_runner_->UnregisterTaskQueue();
     manager_->UnregisterTimeDomain(auto_advancing_time_domain_.get());
   }
 
   base::TimeTicks initial_time_;
   std::unique_ptr<base::SimpleTestTickClock> clock_;
   std::unique_ptr<TestTimeSource> test_time_source_;
   scoped_refptr<cc::OrderedSimpleTaskRunner> mock_task_runner_;
   scoped_refptr<SchedulerTqmDelegate> main_task_runner_;
   std::unique_ptr<TaskQueueManager> manager_;
   scoped_refptr<TaskQueue> task_runner_;
   std::unique_ptr<AutoAdvancingVirtualTimeDomain> auto_advancing_time_domain_;
+  TestTaskTimeTracker test_task_time_tracker_;
 };
 
 namespace {
 void NopTask(bool* task_run) {
   *task_run = true;
 }
 }  // namesapce
 
 TEST_F(AutoAdvancingVirtualTimeDomainTest, VirtualTimeAdvances) {
   base::TimeDelta delay = base::TimeDelta::FromMilliseconds(10);
@@ skipping 18 matching lines @@
   auto_advancing_time_domain_->SetCanAdvanceVirtualTime(false);
 
   mock_task_runner_->RunUntilIdle();
 
   EXPECT_EQ(initial_time_, clock_->NowTicks());
   EXPECT_EQ(initial_time_, auto_advancing_time_domain_->CreateLazyNow().Now());
   EXPECT_FALSE(task_run);
 }
 
 }  // namespace scheduler