Standardize usage of virtual/override/final specifiers.

media/filters/audio_clock_unittest.cc

 // Copyright 2014 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 "media/base/audio_timestamp_helper.h"
 #include "media/base/buffers.h"
 #include "media/filters/audio_clock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace media {
 
 class AudioClockTest : public testing::Test {
  public:
   AudioClockTest()
       : sample_rate_(10), clock_(base::TimeDelta(), sample_rate_) {}
 
-  virtual ~AudioClockTest() {}
+  ~AudioClockTest() override {}
 
   void WroteAudio(int frames_written,
                   int frames_requested,
                   int delay_frames,
                   float playback_rate) {
     clock_.WroteAudio(
         frames_written, frames_requested, delay_frames, playback_rate);
   }
 
   int FrontTimestampInDays() { return clock_.front_timestamp().InDays(); }
@@ skipping 350 matching lines @@
   EXPECT_EQ(huge.InDays(), ContiguousAudioDataBufferedInDays());
 
   // Use huge delay to test calculation of buffered data.
   WroteAudio(
       huge_amount_of_frames, huge_amount_of_frames, huge_amount_of_frames, 1.0);
   EXPECT_EQ((huge * 3).InDays(), FrontTimestampInDays());
   EXPECT_EQ((huge * 2).InDays(), ContiguousAudioDataBufferedInDays());
 }
 
 }  // namespace media