Adds a flag to support "Virtual Time" to the blink scheduler

components/scheduler/child/worker_scheduler_impl_unittest.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 "components/scheduler/child/worker_scheduler_impl.h"
 
 #include "base/callback.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
@@ skipping 74 matching lines @@
 
   base::SimpleTestTickClock* clock_;    // NOT OWNED
   std::vector<std::string>* timeline_;  // NOT OWNED
 };
 
 class WorkerSchedulerImplTest : public testing::Test {
  public:
   WorkerSchedulerImplTest()
       : clock_(new base::SimpleTestTickClock()),
         mock_task_runner_(new cc::OrderedSimpleTaskRunner(clock_.get(), true)),
-        main_task_runner_(
-            SchedulerTaskRunnerDelegateForTest::Create(mock_task_runner_)),
+        main_task_runner_(SchedulerTaskRunnerDelegateForTest::Create(
+            mock_task_runner_,
+            make_scoped_ptr(new TestTimeSource(clock_.get())))),
         scheduler_(
             new WorkerSchedulerImplForTest(main_task_runner_, clock_.get())),
         timeline_(nullptr) {
     clock_->Advance(base::TimeDelta::FromMicroseconds(5000));
-    scheduler_->GetSchedulerHelperForTesting()->SetTimeSourceForTesting(
-        make_scoped_ptr(new TestTimeSource(clock_.get())));
-    scheduler_->GetSchedulerHelperForTesting()
-        ->GetTaskQueueManagerForTesting()
-        ->SetTimeSourceForTesting(
-            make_scoped_ptr(new TestTimeSource(clock_.get())));
   }
 
   ~WorkerSchedulerImplTest() override {}
 
   void TearDown() override {
     // Check that all tests stop posting tasks.
     while (mock_task_runner_->RunUntilIdle()) {
     }
   }
 
@@ skipping 262 matching lines @@
       "run RecordTimelineTask @ 55",
       "IsNotQuiescent @ 55",  // NOTE we have to wait for quiescence.
       "CanEnterLongIdlePeriod @ 355",
       "run TimelineIdleTestTask deadline 405",
       "RunUntilIdle end @ 355"};
 
   EXPECT_THAT(timeline, ElementsAreArray(expected_timeline));
 }
 
 }  // namespace scheduler