Stop the AudioDeviceThread when the IO loop goes away.

content/renderer/media/audio_device.cc

Index: content/renderer/media/audio_device.cc
diff --git a/content/renderer/media/audio_device.cc b/content/renderer/media/audio_device.cc
index 3f89e93ced06d84d6e3524353648f45c4abe2a88..d4e344a7b3bb0aeaa237c5df2e10dbbe0943b3c7 100644
--- a/content/renderer/media/audio_device.cc
+++ b/content/renderer/media/audio_device.cc
@@ -178,6 +178,15 @@ void AudioDevice::ShutDownOnIOThread() {
     stream_id_ = 0;
   }
 
+  // We can run into an issue where ShutDownOnIOThread is called right after
+  // OnStreamCreated is called in cases where Start/Stop are called before we
+  // get the OnStreamCreated callback.  To handle that corner case, we call
+  // Stop(). In most cases, the thread will already be stopped.
+  // Another situation is when the IO thread goes away before Stop() is called
+  // in which case, we cannot use the message loop to close the thread handle
+  // and can't not rely on the main thread existing either.
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  audio_thread_.Stop(NULL);
   audio_callback_.reset();
 }
 
@@ -218,6 +227,7 @@ void AudioDevice::OnStreamCreated(
     return;
   }
 
+  DCHECK(audio_thread_.IsStopped());
   audio_callback_.reset(new AudioDevice::AudioThreadCallback(audio_parameters_,
       handle, length, callback_));
   audio_thread_.Start(audio_callback_.get(), socket_handle, "AudioDevice");
@@ -234,6 +244,7 @@ void AudioDevice::Send(IPC::Message* message) {
 }
 
 void AudioDevice::WillDestroyCurrentMessageLoop() {
+  LOG(ERROR) << "IO loop going away before the audio device has been stopped";
   ShutDownOnIOThread();
 }