Add polling and audio check to copresence.

components/copresence/mediums/audio/audio_recorder_impl.cc

Index: components/copresence/mediums/audio/audio_recorder_impl.cc
diff --git a/components/copresence/mediums/audio/audio_recorder_impl.cc b/components/copresence/mediums/audio/audio_recorder_impl.cc
index 25db15194694720084f3fd6d97204440727d72b2..f0240b29ddc479aef5fbe9dee0db3504f2986fff 100644
--- a/components/copresence/mediums/audio/audio_recorder_impl.cc
+++ b/components/copresence/mediums/audio/audio_recorder_impl.cc
@@ -144,6 +144,7 @@ void AudioRecorderImpl::RecordOnAudioThread() {
   if (!stream_ || is_recording_)
     return;
 
+  VLOG(3) << "Starting recording.";
   converter_->Reset();
   stream_->Start(this);
   is_recording_ = true;
@@ -154,6 +155,7 @@ void AudioRecorderImpl::StopOnAudioThread() {
   if (!stream_ || !is_recording_)
     return;
 
+  VLOG(3) << "Stopping recording.";
   stream_->Stop();
   is_recording_ = false;
 }