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

base/debug/trace_event_unittest.cc

Index: base/debug/trace_event_unittest.cc
diff --git a/base/debug/trace_event_unittest.cc b/base/debug/trace_event_unittest.cc
index 85cf4ebcb6d4c8ab775ca4ea424f2a6016bc511a..30ad797e060d96f023da990d15bb6c228a42b5d4 100644
--- a/base/debug/trace_event_unittest.cc
+++ b/base/debug/trace_event_unittest.cc
@@ -125,7 +125,7 @@ class TraceEventTestFixture : public testing::Test {
                    base::Unretained(flush_complete_event)));
   }
 
-  virtual void SetUp() override {
+  void SetUp() override {
     const char* name = PlatformThread::GetName();
     old_thread_name_ = name ? strdup(name) : NULL;
 
@@ -136,7 +136,7 @@ class TraceEventTestFixture : public testing::Test {
     trace_buffer_.SetOutputCallback(json_output_.GetCallback());
     event_watch_notification_ = 0;
   }
-  virtual void TearDown() override {
+  void TearDown() override {
     if (TraceLog::GetInstance())
       EXPECT_FALSE(TraceLog::GetInstance()->IsEnabled());
     PlatformThread::SetName(old_thread_name_ ? old_thread_name_ : "");
@@ -2215,12 +2215,12 @@ TEST_F(TraceEventTestFixture, PrimitiveArgs) {
 
 class TraceEventCallbackTest : public TraceEventTestFixture {
  public:
-  virtual void SetUp() override {
+  void SetUp() override {
     TraceEventTestFixture::SetUp();
     ASSERT_EQ(NULL, s_instance);
     s_instance = this;
   }
-  virtual void TearDown() override {
+  void TearDown() override {
     TraceLog::GetInstance()->SetDisabled();
     ASSERT_TRUE(!!s_instance);
     s_instance = NULL;