Update {virtual,override} to follow C++11 style in media.

media/audio/win/audio_low_latency_input_win_unittest.cc

Index: media/audio/win/audio_low_latency_input_win_unittest.cc
diff --git a/media/audio/win/audio_low_latency_input_win_unittest.cc b/media/audio/win/audio_low_latency_input_win_unittest.cc
index 69a24f8b5e8206a10ef6123e2c1850f294fae259..e2e7a0393ffafe97f292248020e95926b6cd021d 100644
--- a/media/audio/win/audio_low_latency_input_win_unittest.cc
+++ b/media/audio/win/audio_low_latency_input_win_unittest.cc
@@ -62,16 +62,16 @@ class FakeAudioInputCallback : public AudioInputStream::AudioInputCallback {
     data_event_.Wait();
   }
 
-  virtual void OnData(AudioInputStream* stream,
-                      const AudioBus* src,
-                      uint32 hardware_delay_bytes,
-                      double volume) override {
+  void OnData(AudioInputStream* stream,
+              const AudioBus* src,
+              uint32 hardware_delay_bytes,
+              double volume) override {
     EXPECT_NE(hardware_delay_bytes, 0u);
     num_received_audio_frames_ += src->frames();
     data_event_.Signal();
   }
 
-  virtual void OnError(AudioInputStream* stream) override {
+  void OnError(AudioInputStream* stream) override {
     error_ = true;
   }