Ensures that audio tasks cannot run after AudioManager is deleted.

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 2bba0b2268a0c937480ce01b6fe56ec2000ebf94..5f20affe5f80efca5b6dcba295abc892f2ba676d 100644
--- a/media/audio/audio_input_unittest.cc
+++ b/media/audio/audio_input_unittest.cc
@@ -59,7 +59,7 @@ class AudioInputTest : public testing::Test {
     base::RunLoop().RunUntilIdle();
   }
 
-  ~AudioInputTest() override {}
+  ~AudioInputTest() override { audio_manager_->Shutdown(); }
 
  protected:
   bool InputDevicesAvailable() {
@@ -152,7 +152,7 @@ class AudioInputTest : public testing::Test {
   void OnLogMessage(const std::string& message) {}
 
   base::TestMessageLoop message_loop_;
-  ScopedAudioManagerPtr audio_manager_;
+  std::unique_ptr<AudioManager> audio_manager_;
   AudioInputStream* audio_input_stream_;
 
  private: