Standardize usage of virtual/override/final in components/

components/metrics/metrics_log_unittest.cc

Index: components/metrics/metrics_log_unittest.cc
diff --git a/components/metrics/metrics_log_unittest.cc b/components/metrics/metrics_log_unittest.cc
index eb852273185bd299d51ee72207f494a316ad24ff..da3838277643d4eecfbd37ff477e292c597bdefc 100644
--- a/components/metrics/metrics_log_unittest.cc
+++ b/components/metrics/metrics_log_unittest.cc
@@ -53,7 +53,7 @@ class TestMetricsLog : public MetricsLog {
     InitPrefs();
   }
 
-  virtual ~TestMetricsLog() {}
+  ~TestMetricsLog() override {}
 
   const ChromeUserMetricsExtension& uma_proto() const {
     return *MetricsLog::uma_proto();
@@ -69,9 +69,8 @@ class TestMetricsLog : public MetricsLog {
                       base::Int64ToString(kEnabledDate));
   }
 
-  virtual void GetFieldTrialIds(
-      std::vector<variations::ActiveGroupId>* field_trial_ids) const
-      override {
+  void GetFieldTrialIds(
+      std::vector<variations::ActiveGroupId>* field_trial_ids) const override {
     ASSERT_TRUE(field_trial_ids->empty());
 
     for (size_t i = 0; i < arraysize(kFieldTrialIds); ++i) {