Standardize usage of virtual/override/final specifiers.

media/filters/audio_file_reader_unittest.cc

Index: media/filters/audio_file_reader_unittest.cc
diff --git a/media/filters/audio_file_reader_unittest.cc b/media/filters/audio_file_reader_unittest.cc
index ba264d684f45176aeb7a51134b4b3433277e65a1..6b9bf9d9cb17cd1ecb7613c39c1d41f3900589b8 100644
--- a/media/filters/audio_file_reader_unittest.cc
+++ b/media/filters/audio_file_reader_unittest.cc
@@ -20,7 +20,7 @@ namespace media {
 class AudioFileReaderTest : public testing::Test {
  public:
   AudioFileReaderTest() : packet_verification_disabled_(false) {}
-  virtual ~AudioFileReaderTest() {}
+  ~AudioFileReaderTest() override {}
 
   void Initialize(const char* filename) {
     data_ = ReadTestDataFile(filename);