Standardize usage of virtual/override/final in media/

media/audio/audio_input_unittest.cc

Index: media/audio/audio_input_unittest.cc
diff --git a/media/audio/audio_input_unittest.cc b/media/audio/audio_input_unittest.cc
index 3c977b05253f021b8105ba634a0a74847b63b3a0..9b3e71a5ddf2dcd3f8eb1abcb550a64d0f24aacb 100644
--- a/media/audio/audio_input_unittest.cc
+++ b/media/audio/audio_input_unittest.cc
@@ -23,15 +23,13 @@ class TestInputCallback : public AudioInputStream::AudioInputCallback {
       : callback_count_(0),
         had_error_(0) {
   }
-  virtual void OnData(AudioInputStream* stream,
-                      const AudioBus* source,
-                      uint32 hardware_delay_bytes,
-                      double volume) override {
+  void OnData(AudioInputStream* stream,
+              const AudioBus* source,
+              uint32 hardware_delay_bytes,
+              double volume) override {
     ++callback_count_;
   }
-  virtual void OnError(AudioInputStream* stream) override {
-    ++had_error_;
-  }
+  void OnError(AudioInputStream* stream) override { ++had_error_; }
   // Returns how many times OnData() has been called.
   int callback_count() const {
     return callback_count_;