Standardize usage of virtual/override/final specifiers.

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 9b3e71a5ddf2dcd3f8eb1abcb550a64d0f24aacb..1d5470b0a1d522391aa7cffba0a66f3fce2bd096 100644
--- a/media/audio/audio_input_unittest.cc
+++ b/media/audio/audio_input_unittest.cc
@@ -54,9 +54,7 @@ class AudioInputTest : public testing::Test {
     base::RunLoop().RunUntilIdle();
   }
 
-  virtual ~AudioInputTest() {
-    base::RunLoop().RunUntilIdle();
-  }
+  ~AudioInputTest() override { base::RunLoop().RunUntilIdle(); }
 
  protected:
   AudioManager* audio_manager() { return audio_manager_.get(); }