Standardize usage of virtual/override/final in media/

media/base/demuxer_perftest.cc

Index: media/base/demuxer_perftest.cc
diff --git a/media/base/demuxer_perftest.cc b/media/base/demuxer_perftest.cc
index 2504c8e9bf594b84f6f4db6d906291b719ee99df..339cfe136a26f0accbfc8853fe3147db6cf864b1 100644
--- a/media/base/demuxer_perftest.cc
+++ b/media/base/demuxer_perftest.cc
@@ -22,16 +22,16 @@ static const int kBenchmarkIterations = 100;
 class DemuxerHostImpl : public media::DemuxerHost {
  public:
   DemuxerHostImpl() {}
-  virtual ~DemuxerHostImpl() {}
+  ~DemuxerHostImpl() override {}
 
   // DemuxerHost implementation.
-  virtual void AddBufferedTimeRange(base::TimeDelta start,
-                                    base::TimeDelta end) override {}
-  virtual void SetDuration(base::TimeDelta duration) override {}
-  virtual void OnDemuxerError(media::PipelineStatus error) override {}
-  virtual void AddTextStream(media::DemuxerStream* text_stream,
-                             const media::TextTrackConfig& config) override {}
-  virtual void RemoveTextStream(media::DemuxerStream* text_stream) override {}
+  void AddBufferedTimeRange(base::TimeDelta start,
+                            base::TimeDelta end) override {}
+  void SetDuration(base::TimeDelta duration) override {}
+  void OnDemuxerError(media::PipelineStatus error) override {}
+  void AddTextStream(media::DemuxerStream* text_stream,
+                     const media::TextTrackConfig& config) override {}
+  void RemoveTextStream(media::DemuxerStream* text_stream) override {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DemuxerHostImpl);