Ensures that audio tasks cannot run after AudioManager is deleted.

content/browser/renderer_host/media/media_stream_dispatcher_host_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 "content/browser/renderer_host/media/media_stream_dispatcher_host.h"
 
 #include <stddef.h>
 #include <memory>
 #include <queue>
 #include <string>
@@ skipping 409 matching lines @@
     for (size_t i = 0; i < devices.size(); ++i) {
       if (!devices[i].device.name.empty())
         return false;
     }
     return true;
   }
 
   scoped_refptr<MockMediaStreamDispatcherHost> host_;
   std::unique_ptr<MediaStreamManager> media_stream_manager_;
   content::TestBrowserThreadBundle thread_bundle_;
-  std::unique_ptr<media::AudioManager, media::AudioManagerDeleter>
-      audio_manager_;
+  std::unique_ptr<media::AudioManager> audio_manager_;
   std::unique_ptr<media::AudioSystem> audio_system_;
   MockMediaStreamUIProxy* stream_ui_;
   ContentBrowserClient* old_browser_client_;
   std::unique_ptr<ContentClient> content_client_;
   content::TestBrowserContext browser_context_;
   media::AudioDeviceDescriptions physical_audio_devices_;
   media::VideoCaptureDeviceDescriptors physical_video_devices_;
   url::Origin origin_;
   media::FakeVideoCaptureDeviceFactory* video_capture_device_factory_;
 };
@@ skipping 411 matching lines @@
   base::RunLoop run_loop;
   EXPECT_CALL(*host_.get(), OnDeviceStopped(kRenderId))
       .WillOnce(testing::InvokeWithoutArgs(&run_loop, &base::RunLoop::Quit));
   media_stream_manager_->media_devices_manager()->OnDevicesChanged(
       base::SystemMonitor::DEVTYPE_VIDEO_CAPTURE);
 
   run_loop.Run();
 }
 
 };  // namespace content