DCHECK that audio devices are stopped prior to destruction.

media/audio/audio_input_device.cc

Index: media/audio/audio_input_device.cc
diff --git a/media/audio/audio_input_device.cc b/media/audio/audio_input_device.cc
index aa44d9d7552e0c4f40cf550465aa891fdf8edec9..07b966cba0ce817139cc6696953e1113459af23c 100644
--- a/media/audio/audio_input_device.cc
+++ b/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());