Add virtual and OVERRIDE to base/ implementation files

base/threading/worker_pool_posix_unittest.cc

Index: base/threading/worker_pool_posix_unittest.cc
diff --git a/base/threading/worker_pool_posix_unittest.cc b/base/threading/worker_pool_posix_unittest.cc
index a8d9218b9cda5fb86a5811311bc1fe8761c84989..49f6570aa4e144ee2d3de97df92b433c635c8497 100644
--- a/base/threading/worker_pool_posix_unittest.cc
+++ b/base/threading/worker_pool_posix_unittest.cc
@@ -97,11 +97,11 @@ class PosixDynamicThreadPoolTest : public testing::Test {
         num_waiting_to_start_cv_(&num_waiting_to_start_lock_),
         start_(true, false) {}
 
-  virtual void SetUp() {
+  virtual void SetUp() OVERRIDE {
     peer_.set_num_idle_threads_cv(new ConditionVariable(peer_.lock()));
   }
 
-  virtual void TearDown() {
+  virtual void TearDown() OVERRIDE {
     // Wake up the idle threads so they can terminate.
     if (pool_.get()) pool_->Terminate();
   }