DCHECK that audio devices are stopped prior to destruction.

This is required (and documented by a comment in the header file), so the DCHECKs are motivated.

BUG=711400
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2828233002
Cr-Commit-Position: refs/heads/master@{#466898}

media/audio/audio_input_device.cc

@@ -191,7 +191,17 @@ void AudioInputDevice::OnIPCClosed() {
   ipc_.reset();
 }
 
-AudioInputDevice::~AudioInputDevice() {}
+AudioInputDevice::~AudioInputDevice() {
+#if DCHECK_IS_ON()
+  // Make sure we've stopped the stream properly before destructing |this|.
+  DCHECK(audio_thread_lock_.Try());
+  DCHECK_LE(state_, IDLE);
+  DCHECK(!audio_thread_);
+  DCHECK(!audio_callback_);
+  DCHECK(!stopping_hack_);
+  audio_thread_lock_.Release();
+#endif  // DCHECK_IS_ON()
+}
 
 void AudioInputDevice::StartUpOnIOThread() {
   DCHECK(task_runner()->BelongsToCurrentThread());

media/audio/audio_input_device_unittest.cc

@@ -93,6 +93,8 @@ TEST(AudioInputDeviceTest, FailToCreateStream) {
   EXPECT_CALL(callback, OnCaptureError(_))
       .WillOnce(QuitLoop(io_loop.task_runner()));
   base::RunLoop().Run();
+  device->Stop();
+  base::RunLoop().RunUntilIdle();
 }
 
 ACTION_P5(ReportOnStreamCreated, device, handle, socket, length, segments) {
@@ -139,5 +141,8 @@ TEST(AudioInputDeviceTest, CreateStream) {
   EXPECT_CALL(callback, OnCaptureStarted())
       .WillOnce(QuitLoop(io_loop.task_runner()));
   base::RunLoop().Run();
+  device->Stop();
+  base::RunLoop().RunUntilIdle();
 }
+
 }  // namespace media.

media/audio/audio_output_device.cc

@@ -96,7 +96,17 @@ void AudioOutputDevice::Initialize(const AudioParameters& params,
   callback_ = callback;
 }
 
-AudioOutputDevice::~AudioOutputDevice() {}
+AudioOutputDevice::~AudioOutputDevice() {
+#if DCHECK_IS_ON()
+  // Make sure we've stopped the stream properly before destructing |this|.
+  DCHECK(audio_thread_lock_.Try());
+  DCHECK_LE(state_, IDLE);
+  DCHECK(!audio_thread_);
+  DCHECK(!audio_callback_);
+  DCHECK(!stopping_hack_);
+  audio_thread_lock_.Release();
+#endif  // DCHECK_IS_ON()
+}
 
 void AudioOutputDevice::RequestDeviceAuthorization() {
   task_runner()->PostTask(

media/audio/audio_output_device_unittest.cc

@@ -158,6 +158,10 @@ AudioOutputDeviceTest::~AudioOutputDeviceTest() {
 }
 
 void AudioOutputDeviceTest::CreateDevice(const std::string& device_id) {
+  // Make sure the previous device is properly cleaned up.
+  if (audio_device_)
+    StopAudioDevice();
+
   audio_output_ipc_ = new MockAudioOutputIPC();
   audio_device_ = new AudioOutputDevice(
       base::WrapUnique(audio_output_ipc_), io_loop_.task_runner(), 0, device_id,