Standardize usage of virtual/override/final in base/

base/tools_sanity_unittest.cc

Index: base/tools_sanity_unittest.cc
diff --git a/base/tools_sanity_unittest.cc b/base/tools_sanity_unittest.cc
index d61d1c22785ee78031ff6ee113fb95c7962e0315..2ddaf89dd490806d5941051710b78c6b6d923487 100644
--- a/base/tools_sanity_unittest.cc
+++ b/base/tools_sanity_unittest.cc
@@ -238,8 +238,8 @@ namespace {
 class TOOLS_SANITY_TEST_CONCURRENT_THREAD : public PlatformThread::Delegate {
  public:
   explicit TOOLS_SANITY_TEST_CONCURRENT_THREAD(bool *value) : value_(value) {}
-  virtual ~TOOLS_SANITY_TEST_CONCURRENT_THREAD() {}
-  virtual void ThreadMain() override {
+  ~TOOLS_SANITY_TEST_CONCURRENT_THREAD() override {}
+  void ThreadMain() override {
     *value_ = true;
 
     // Sleep for a few milliseconds so the two threads are more likely to live
@@ -254,8 +254,8 @@ class TOOLS_SANITY_TEST_CONCURRENT_THREAD : public PlatformThread::Delegate {
 class ReleaseStoreThread : public PlatformThread::Delegate {
  public:
   explicit ReleaseStoreThread(base::subtle::Atomic32 *value) : value_(value) {}
-  virtual ~ReleaseStoreThread() {}
-  virtual void ThreadMain() override {
+  ~ReleaseStoreThread() override {}
+  void ThreadMain() override {
     base::subtle::Release_Store(value_, kMagicValue);
 
     // Sleep for a few milliseconds so the two threads are more likely to live
@@ -270,8 +270,8 @@ class ReleaseStoreThread : public PlatformThread::Delegate {
 class AcquireLoadThread : public PlatformThread::Delegate {
  public:
   explicit AcquireLoadThread(base::subtle::Atomic32 *value) : value_(value) {}
-  virtual ~AcquireLoadThread() {}
-  virtual void ThreadMain() override {
+  ~AcquireLoadThread() override {}
+  void ThreadMain() override {
     // Wait for the other thread to make Release_Store
     PlatformThread::Sleep(TimeDelta::FromMilliseconds(100));
     base::subtle::Acquire_Load(value_);