Standardize usage of virtual/override/final specifiers.

components/network_time/network_time_tracker_unittest.cc

Index: components/network_time/network_time_tracker_unittest.cc
diff --git a/components/network_time/network_time_tracker_unittest.cc b/components/network_time/network_time_tracker_unittest.cc
index a401fff97848af6a03d651c3f15698e4b3b23679..b2352c0a697140d8d390ee674949934902fed93a 100644
--- a/components/network_time/network_time_tracker_unittest.cc
+++ b/components/network_time/network_time_tracker_unittest.cc
@@ -42,9 +42,9 @@ class TestTickClock : public base::TickClock {
 
 class NetworkTimeTrackerTest : public testing::Test {
  public:
-  virtual ~NetworkTimeTrackerTest() {}
+  ~NetworkTimeTrackerTest() override {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
     NetworkTimeTracker::RegisterPrefs(pref_service_.registry());
 
     now_ = base::Time::NowFromSystemTime();