Standardize usage of virtual/override/final specifiers in base/.

base/tracked_objects_unittest.cc

 // Copyright (c) 2012 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.
 
 // Test of classes in the tracked_objects.h classes.
 
 #include "base/tracked_objects.h"
 
 #include <stddef.h>
 
@@ skipping 16 matching lines @@
   TrackedObjectsTest() {
     // On entry, leak any database structures in case they are still in use by
     // prior threads.
     ThreadData::ShutdownSingleThreadedCleanup(true);
 
     test_time_ = 0;
     ThreadData::SetAlternateTimeSource(&TrackedObjectsTest::GetTestTime);
     ThreadData::now_function_is_time_ = true;
   }
 
-  virtual ~TrackedObjectsTest() {
+  ~TrackedObjectsTest() override {
     // We should not need to leak any structures we create, since we are
     // single threaded, and carefully accounting for items.
     ThreadData::ShutdownSingleThreadedCleanup(false);
   }
 
   // Reset the profiler state.
   void Reset() {
     ThreadData::ShutdownSingleThreadedCleanup(false);
     test_time_ = 0;
   }
@@ skipping 773 matching lines @@
   EXPECT_EQ(2, process_data.tasks[t1].death_data.run_duration_sample);
   EXPECT_EQ(1, process_data.tasks[t1].death_data.queue_duration_sum);
   EXPECT_EQ(1, process_data.tasks[t1].death_data.queue_duration_max);
   EXPECT_EQ(1, process_data.tasks[t1].death_data.queue_duration_sample);
   EXPECT_EQ(kMainThreadName, process_data.tasks[t1].death_thread_name);
   EXPECT_EQ(0u, process_data.descendants.size());
   EXPECT_EQ(base::GetCurrentProcId(), process_data.process_id);
 }
 
 }  // namespace tracked_objects