Ensures that audio tasks cannot run after AudioManager is deleted.

media/audio/pulse/audio_manager_pulse.cc

 // Copyright 2013 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 "media/audio/pulse/audio_manager_pulse.h"
 
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
@@ skipping 45 matching lines @@
                        std::move(worker_task_runner),
                        audio_log_factory),
       input_mainloop_(NULL),
       input_context_(NULL),
       devices_(NULL),
       native_input_sample_rate_(0),
       native_channel_count_(0) {
   SetMaxOutputStreamsAllowed(kMaxOutputStreams);
 }
 
-AudioManagerPulse::~AudioManagerPulse() {
-  Shutdown();
-  // The Pulse objects are the last things to be destroyed since Shutdown()
-  // needs them.
-  DestroyPulse();
-}
+AudioManagerPulse::~AudioManagerPulse() = default;
 
 bool AudioManagerPulse::Init() {
   // TODO(alokp): Investigate if InitPulse can happen on the audio thread.
   // It currently needs to happen on the main thread so that is InitPulse fails,
   // we can fallback to ALSA implementation. Initializing it on audio thread
   // would unblock the main thread and make InitPulse consistent with
   // DestroyPulse which happens on the audio thread.
   return InitPulse();
 }
 
-// Implementation of AudioManager.
+void AudioManagerPulse::Shutdown() {
+  AudioManagerBase::Shutdown();
+  // The Pulse objects are the last things to be destroyed since Shutdown()
+  // needs them.
+  DestroyPulse();
+}
+
 bool AudioManagerPulse::HasAudioOutputDevices() {
   AudioDeviceNames devices;
   GetAudioOutputDeviceNames(&devices);
   return !devices.empty();
 }
 
 bool AudioManagerPulse::HasAudioInputDevices() {
   AudioDeviceNames devices;
   GetAudioInputDeviceNames(&devices);
   return !devices.empty();
@@ skipping 256 matching lines @@
                                                   const pa_server_info* info,
                                                   void* user_data) {
   AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);
 
   manager->native_input_sample_rate_ = info->sample_spec.rate;
   manager->native_channel_count_ = info->sample_spec.channels;
   pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
 }
 
 }  // namespace media