Scheduler/child/TimeSource could be replaced with base/time/DefaultTickClock.

components/scheduler/child/test_time_source.h

 // 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.
 
 #ifndef COMPONENTS_SCHEDULER_CHILD_TEST_TIME_SOURCE_H_
 #define COMPONENTS_SCHEDULER_CHILD_TEST_TIME_SOURCE_H_
 
 #include "base/memory/ref_counted.h"
-#include "components/scheduler/child/time_source.h"
+#include "base/time/tick_clock.h"
 
 namespace cc {
 class TestNowSource;
 }
 
 namespace scheduler {
 
-class TestTimeSource : public TimeSource {
+class TestTimeSource : public base::TickClock {
  public:
   explicit TestTimeSource(scoped_refptr<cc::TestNowSource> time_source);
   ~TestTimeSource() override;
 
-  base::TimeTicks Now() const override;
+  base::TimeTicks NowTicks() override;
 
  private:
   scoped_refptr<cc::TestNowSource> time_source_;
 
   DISALLOW_COPY_AND_ASSIGN(TestTimeSource);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_CHILD_TEST_TIME_SOURCE_H_