Adding AGC stats in combination with report of missing input audio on Mac

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 22a0455e313277bc31b9f396a6e0fa7d53f5a059..601815a912d63fa7361dd10240c8c4d037ff3a47 100644
--- a/media/audio/mac/audio_low_latency_input_mac.cc
+++ b/media/audio/mac/audio_low_latency_input_mac.cc
@@ -803,6 +803,8 @@ void AUAudioInputStream::AddHistogramsForFailedStartup() {
                             manager_->low_latency_input_streams());
   UMA_HISTOGRAM_COUNTS_1000("Media.Audio.NumberOfBasicInputStreamsMac",
                             manager_->basic_input_streams());
+  UMA_HISTOGRAM_BOOLEAN("Media.Audio.AutomaticGainControlMac",
+                        GetAutomaticGainControl());
 }
 
 }  // namespace media