Ensures that audio tasks cannot run after AudioManager is deleted.

content/browser/renderer_host/media/video_capture_unittest.cc

Index: content/browser/renderer_host/media/video_capture_unittest.cc
diff --git a/content/browser/renderer_host/media/video_capture_unittest.cc b/content/browser/renderer_host/media/video_capture_unittest.cc
index 9cb9347eb441e6e65ec1b39a32f429c050017b59..3cb283c2008087d861ced1e743b0198180ea3015 100644
--- a/content/browser/renderer_host/media/video_capture_unittest.cc
+++ b/content/browser/renderer_host/media/video_capture_unittest.cc
@@ -29,6 +29,7 @@
 #include "content/test/test_content_browser_client.h"
 #include "media/audio/audio_system_impl.h"
 #include "media/audio/mock_audio_manager.h"
+#include "media/audio/test_audio_thread.h"
 #include "media/base/media_switches.h"
 #include "media/capture/video_capture_types.h"
 #include "mojo/public/cpp/bindings/binding.h"
@@ -114,12 +115,13 @@ class VideoCaptureTest : public testing::Test,
  public:
   VideoCaptureTest()
       : thread_bundle_(content::TestBrowserThreadBundle::IO_MAINLOOP),
-        audio_manager_(
-            new media::MockAudioManager(base::ThreadTaskRunnerHandle::Get())),
+        audio_manager_(new media::MockAudioManager(
+            base::MakeUnique<media::TestAudioThread>())),
         audio_system_(media::AudioSystemImpl::Create(audio_manager_.get())),
         task_runner_(base::ThreadTaskRunnerHandle::Get()),
         opened_session_id_(kInvalidMediaCaptureSessionId),
         observer_binding_(this) {}
+  ~VideoCaptureTest() override { audio_manager_->Shutdown(); }
 
   void SetUp() override {
     SetBrowserClientForTesting(&browser_client_);
@@ -309,9 +311,7 @@ class VideoCaptureTest : public testing::Test,
   StrictMock<MockMediaStreamRequester> stream_requester_;
   std::unique_ptr<MediaStreamManager> media_stream_manager_;
   const content::TestBrowserThreadBundle thread_bundle_;
-  // |audio_manager_| needs to outlive |thread_bundle_| because it uses the
-  // underlying message loop.
-  media::ScopedAudioManagerPtr audio_manager_;
+  std::unique_ptr<media::AudioManager> audio_manager_;
   std::unique_ptr<media::AudioSystem> audio_system_;
   content::TestBrowserContext browser_context_;
   content::TestContentBrowserClient browser_client_;