Add virtual and OVERRIDE to base/ implementation files

base/synchronization/waitable_event_watcher_unittest.cc

 // Copyright (c) 2011 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.
 
 #include "base/message_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/synchronization/waitable_event_watcher.h"
 #include "base/threading/platform_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 namespace {
 
 class QuitDelegate : public WaitableEventWatcher::Delegate {
  public:
-  virtual void OnWaitableEventSignaled(WaitableEvent* event) {
+  virtual void OnWaitableEventSignaled(WaitableEvent* event) OVERRIDE {
     MessageLoop::current()->Quit();
   }
 };
 
 class DecrementCountDelegate : public WaitableEventWatcher::Delegate {
  public:
   explicit DecrementCountDelegate(int* counter) : counter_(counter) {
   }
-  virtual void OnWaitableEventSignaled(WaitableEvent* object) {
+  virtual void OnWaitableEventSignaled(WaitableEvent* object) OVERRIDE {
     --(*counter_);
   }
  private:
   int* counter_;
 };
 
 void RunTest_BasicSignal(MessageLoop::Type message_loop_type) {
   MessageLoop message_loop(message_loop_type);
 
   // A manual-reset event that is not yet signaled.
@@ skipping 119 matching lines @@
 #else
 #define MAYBE_DeleteUnder DeleteUnder
 #endif
 TEST(WaitableEventWatcherTest, MAYBE_DeleteUnder) {
   RunTest_DeleteUnder(MessageLoop::TYPE_DEFAULT);
   RunTest_DeleteUnder(MessageLoop::TYPE_IO);
   RunTest_DeleteUnder(MessageLoop::TYPE_UI);
 }
 
 }  // namespace base