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

components/scheduler/renderer/task_cost_estimator_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 "base/test/simple_test_tick_clock.h"
 #include "components/scheduler/base/test_time_source.h"
 #include "components/scheduler/renderer/task_cost_estimator.h"
 
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace scheduler {
 
 class TaskCostEstimatorTest : public testing::Test {
  public:
   TaskCostEstimatorTest() {}
   ~TaskCostEstimatorTest() override {}
 
-  void SetUp() override {}
+  void SetUp() override {
+    test_time_source_.reset(new TestTimeSource(&clock_));
+  }
 
   base::SimpleTestTickClock clock_;
+  scoped_ptr<TestTimeSource> test_time_source_;
 };
 
 class TaskCostEstimatorForTest : public TaskCostEstimator {
  public:
-  TaskCostEstimatorForTest(base::SimpleTestTickClock* clock,
+  TaskCostEstimatorForTest(TestTimeSource* test_time_source,
                            int sample_count,
                            double estimation_percentile)
-      : TaskCostEstimator(sample_count, estimation_percentile) {
-    SetTimeSourceForTesting(make_scoped_ptr(new TestTimeSource(clock)));
-  }
+      : TaskCostEstimator(test_time_source,
+                          sample_count,
+                          estimation_percentile) {}
 };
 
 TEST_F(TaskCostEstimatorTest, BasicEstimation) {
-  TaskCostEstimatorForTest estimator(&clock_, 1, 100);
+  TaskCostEstimatorForTest estimator(test_time_source_.get(), 1, 100);
   base::PendingTask task(FROM_HERE, base::Closure());
 
   estimator.WillProcessTask(task);
   clock_.Advance(base::TimeDelta::FromMilliseconds(500));
   estimator.DidProcessTask(task);
 
   EXPECT_EQ(base::TimeDelta::FromMilliseconds(500),
             estimator.expected_task_duration());
 }
 
 TEST_F(TaskCostEstimatorTest, Clear) {
-  TaskCostEstimatorForTest estimator(&clock_, 1, 100);
+  TaskCostEstimatorForTest estimator(test_time_source_.get(), 1, 100);
   base::PendingTask task(FROM_HERE, base::Closure());
 
   estimator.WillProcessTask(task);
   clock_.Advance(base::TimeDelta::FromMilliseconds(500));
   estimator.DidProcessTask(task);
 
   estimator.Clear();
 
   EXPECT_EQ(base::TimeDelta(), estimator.expected_task_duration());
 }
 
 TEST_F(TaskCostEstimatorTest, NestedRunLoop) {
-  TaskCostEstimatorForTest estimator(&clock_, 1, 100);
+  TaskCostEstimatorForTest estimator(test_time_source_.get(), 1, 100);
   base::PendingTask task(FROM_HERE, base::Closure());
 
   // Make sure we ignore the tasks inside the nested run loop.
   estimator.WillProcessTask(task);
   estimator.WillProcessTask(task);
   clock_.Advance(base::TimeDelta::FromMilliseconds(500));
   estimator.DidProcessTask(task);
   clock_.Advance(base::TimeDelta::FromMilliseconds(500));
   estimator.DidProcessTask(task);
 
   EXPECT_EQ(base::TimeDelta::FromMilliseconds(1000),
             estimator.expected_task_duration());
 }
 
 }  // namespace scheduler