Changes error handling for AudioUnitRender on Mac OSX

media/audio/mac/audio_low_latency_input_mac.cc

Index: media/audio/mac/audio_low_latency_input_mac.cc
diff --git a/media/audio/mac/audio_low_latency_input_mac.cc b/media/audio/mac/audio_low_latency_input_mac.cc
index eb328af660213876037eed230865b7e8ca124133..9baaf2701caf34e33d1e442554c9260666ed80e6 100644
--- a/media/audio/mac/audio_low_latency_input_mac.cc
+++ b/media/audio/mac/audio_low_latency_input_mac.cc
@@ -586,9 +586,7 @@ OSStatus AUAudioInputStream::InputProc(void* user_data,
   if (result) {
     UMA_HISTOGRAM_SPARSE_SLOWLY("Media.AudioInputCbErrorMac", result);
     OSSTATUS_DLOG(ERROR, result) << "AudioUnitRender() failed ";
-    if (result != kAudioUnitErr_TooManyFramesToProcess) {
-      audio_input->HandleError(result);
-    } else {
+    if (result == kAudioUnitErr_TooManyFramesToProcess) {
       DCHECK(!audio_input->last_success_time_.is_null());
       // We delay stopping the stream for kAudioUnitErr_TooManyFramesToProcess
       // since it has been observed that some USB headsets can cause this error
@@ -604,6 +602,18 @@ OSStatus AUAudioInputStream::InputProc(void* user_data,
         DLOG(ERROR) << "Too long sequence of TooManyFramesToProcess errors!";
         audio_input->HandleError(result);
       }
+    } else if (result == kAudioUnitErr_CannotDoInCurrentContext) {
+      // Returned when an audio unit is in a state where it can't perform the
+      // requested action now - but it could later.
+      // TODO(henrika): figure out why we see this error message.
+      DLOG(ERROR) << "kAudioUnitErr_CannotDoInCurrentContext";

[tommi (sloooow) - chröme, 2016/01/21 12:36:12]

maybe LOG(ERROR) for now?  In case this could be useful for in-the-field
troubleshooting.

[tommi (sloooow) - chröme, 2016/01/21 12:42:42]

what about this comment?

[henrika (OOO until Aug 14), 2016/01/21 12:44:13]

Done. Changed some more to LOG as well. To ensure that we can see these logs in
Canary as well.

[henrika (OOO until Aug 14), 2016/01/21 12:53:08]

Done.

+    } else if (result == kAudioUnitErr_NoConnection) {
+      // There is no connection (generally an audio unit is asked to render
+      // but it has not input from which to gather data).
+      // TODO(henrika): figure out why we see this error message.
+      DLOG(ERROR) << "kAudioUnitErr_NoConnection";

[tommi (sloooow) - chröme, 2016/01/21 12:36:12]

I think we should treat this one like a general case.  If the device isn't
connected, it makes sense to report an error and close the stream.  Logging the
error seems useful though.

[tommi (sloooow) - chröme, 2016/01/21 12:42:42]

LOG(ERROR) could be useful for this error as well (or any other error actually).
 What about adding a LOG(ERROR) just before we call HandleError()?

[henrika (OOO until Aug 14), 2016/01/21 12:44:13]

Done.

[henrika (OOO until Aug 14), 2016/01/21 12:53:08]

It is covered above by OSSTATUS_DLOG(ERROR, result) << "AudioUnitRender() failed
";

+    } else {
+      audio_input->HandleError(result);
     }
     return result;
   }