Standardize usage of virtual/override/final in base/

base/threading/thread_collision_warner_unittest.cc

Index: base/threading/thread_collision_warner_unittest.cc
diff --git a/base/threading/thread_collision_warner_unittest.cc b/base/threading/thread_collision_warner_unittest.cc
index c7c7d0acf20054c2d4d710d8ef1f808476e0124c..26faff404f6593a89125707ed50490e66b54d717 100644
--- a/base/threading/thread_collision_warner_unittest.cc
+++ b/base/threading/thread_collision_warner_unittest.cc
@@ -41,11 +41,9 @@ class AssertReporter : public base::AsserterBase {
   AssertReporter()
       : failed_(false) {}
 
-  virtual void warn() override {
-    failed_ = true;
-  }
+  void warn() override { failed_ = true; }
 
-  virtual ~AssertReporter() {}
+  ~AssertReporter() override {}
 
   bool fail_state() const { return failed_; }
   void reset() { failed_ = false; }
@@ -151,7 +149,7 @@ TEST(ThreadCollisionTest, MTBookCriticalSectionTest) {
     explicit QueueUser(NonThreadSafeQueue& queue)
         : queue_(queue) {}
 
-    virtual void Run() override {
+    void Run() override {
       queue_.push(0);
       queue_.pop();
     }
@@ -209,7 +207,7 @@ TEST(ThreadCollisionTest, MTScopedBookCriticalSectionTest) {
     explicit QueueUser(NonThreadSafeQueue& queue)
         : queue_(queue) {}
 
-    virtual void Run() override {
+    void Run() override {
       queue_.push(0);
       queue_.pop();
     }
@@ -270,7 +268,7 @@ TEST(ThreadCollisionTest, MTSynchedScopedBookCriticalSectionTest) {
         : queue_(queue),
           lock_(lock) {}
 
-    virtual void Run() override {
+    void Run() override {
       {
         base::AutoLock auto_lock(lock_);
         queue_.push(0);
@@ -344,7 +342,7 @@ TEST(ThreadCollisionTest, MTSynchedScopedRecursiveBookCriticalSectionTest) {
         : queue_(queue),
           lock_(lock) {}
 
-    virtual void Run() override {
+    void Run() override {
       {
         base::AutoLock auto_lock(lock_);
         queue_.push(0);