replace 'virtual ... OVERRIDE' with '... override'

base/synchronization/waitable_event_unittest.cc

 // Copyright (c) 2012 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/synchronization/waitable_event.h"
 
 #include "base/compiler_specific.h"
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 60 matching lines @@
     delete ev[i];
 }
 
 class WaitableEventSignaler : public PlatformThread::Delegate {
  public:
   WaitableEventSignaler(double seconds, WaitableEvent* ev)
       : seconds_(seconds),
         ev_(ev) {
   }
 
-  virtual void ThreadMain() OVERRIDE {
+  void ThreadMain() override {
     PlatformThread::Sleep(TimeDelta::FromSecondsD(seconds_));
     ev_->Signal();
   }
 
  private:
   const double seconds_;
   WaitableEvent *const ev_;
 };
 
 TEST(WaitableEventTest, WaitAndDelete) {
@@ skipping 29 matching lines @@
   size_t index = WaitableEvent::WaitMany(ev, 5);
 
   for (unsigned i = 0; i < 5; ++i)
     delete ev[i];
 
   PlatformThread::Join(thread);
   EXPECT_EQ(2u, index);
 }
 
 }  // namespace base