Ensures that audio tasks cannot run after AudioManager is deleted.

media/audio/mac/audio_low_latency_input_mac_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/environment.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 140 matching lines @@
                         fs, 16, samples_per_packet),
         AudioDeviceDescription::kDefaultDeviceId,
         base::Bind(&MacAudioInputTest::OnLogMessage, base::Unretained(this)));
     EXPECT_TRUE(ais);
     return ais;
   }
 
   void OnLogMessage(const std::string& message) { log_message_ = message; }
 
   base::MessageLoop message_loop_;
-  ScopedAudioManagerPtr audio_manager_;
+  std::unique_ptr<AudioManager> audio_manager_;
   std::string log_message_;
 };
 
 // Test Create(), Close().
 TEST_F(MacAudioInputTest, AUAudioInputStreamCreateAndClose) {
   ABORT_AUDIO_TEST_IF_NOT(InputDevicesAvailable());
   AudioInputStream* ais = CreateDefaultAudioInputStream();
   ais->Close();
 }
 
@@ skipping 108 matching lines @@
   WriteToFileAudioSink file_sink(file_name);
   fprintf(stderr, "               >> Speak into the mic while recording...\n");
   ais->Start(&file_sink);
   base::PlatformThread::Sleep(TestTimeouts::action_timeout());
   ais->Stop();
   fprintf(stderr, "               >> Recording has stopped.\n");
   ais->Close();
 }
 
 }  // namespace media