Ensures that audio tasks cannot run after AudioManager is deleted.

media/audio/mac/audio_auhal_mac_unittest.cc

Index: media/audio/mac/audio_auhal_mac_unittest.cc
diff --git a/media/audio/mac/audio_auhal_mac_unittest.cc b/media/audio/mac/audio_auhal_mac_unittest.cc
index 1f68f3d6534ea6cdc21dbd51a4e69b557599370c..7ff663dd5b43fca90f058e8c1f37ff6ae08e204d 100644
--- a/media/audio/mac/audio_auhal_mac_unittest.cc
+++ b/media/audio/mac/audio_auhal_mac_unittest.cc
@@ -13,6 +13,7 @@
 #include "media/audio/audio_manager.h"
 #include "media/audio/audio_unittest_util.h"
 #include "media/audio/mock_audio_source_callback.h"
+#include "media/audio/test_audio_thread.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -39,7 +40,7 @@ class AUHALStreamTest : public testing::Test {
   AUHALStreamTest()
       : message_loop_(base::MessageLoop::TYPE_UI),
         manager_(AudioManager::CreateForTesting(
-            base::ThreadTaskRunnerHandle::Get())),
+            base::MakeUnique<TestAudioThread>())),
         manager_device_info_(manager_.get()) {
     // Wait for the AudioManager to finish any initialization on the audio loop.
     base::RunLoop().RunUntilIdle();
@@ -61,7 +62,7 @@ class AUHALStreamTest : public testing::Test {
 
  protected:
   base::TestMessageLoop message_loop_;
-  ScopedAudioManagerPtr manager_;
+  std::unique_ptr<AudioManager> manager_;
   AudioDeviceInfoAccessorForTests manager_device_info_;
   MockAudioSourceCallback source_;
   std::string log_message_;