Add support for audio input mute detection on all platforms

media/audio/audio_input_controller.cc

Index: media/audio/audio_input_controller.cc
diff --git a/media/audio/audio_input_controller.cc b/media/audio/audio_input_controller.cc
index 72239f0d9c30efbdc80290988e787cee57e1b531..e76aff9bbdc5e40fb75d928561aa95c1050251c3 100644
--- a/media/audio/audio_input_controller.cc
+++ b/media/audio/audio_input_controller.cc
@@ -583,7 +583,24 @@ void AudioInputController::DoLogAudioLevels(float level_dbfs,
   if (!handler_)
     return;
 
-  std::string log_string = base::StringPrintf(
+  std::string log_string;

[tommi (sloooow) - chröme, 2014/10/15 17:00:48]

nit: move this down to where you need it (where print the audio levels)

[henrika (OOO until Aug 14), 2014/10/16 09:58:00]

Done.

+
+  // Detect if the user has enabled hardware mute by pressing the mute
+  // button in audio settings for the selected microphone.
+  const bool microphone_is_muted = stream_->IsMuted();
+  if (microphone_is_muted) {

[tommi (sloooow) - chröme, 2014/10/15 17:00:48]

nit: you don't really need this variable.

[henrika (OOO until Aug 14), 2014/10/16 09:58:00]

Done.

+    LogMicrophoneMuteResult(MICROPHONE_IS_MUTED);
+    log_string = base::StringPrintf(

[tommi (sloooow) - chröme, 2014/10/15 17:00:48]

no need for StringPrintf

[henrika (OOO until Aug 14), 2014/10/16 09:58:00]

Done.

+        "AIC::OnData: microphone is muted!");
+    handler_->OnLog(this, log_string);
+    // Return early if microphone is muted. No idea adding logs and UMA stats

[tommi (sloooow) - chröme, 2014/10/15 17:00:48]

nit: "No idea" -> "No need to" (etc)

[henrika (OOO until Aug 14), 2014/10/16 09:58:00]

Done.

+    // of audio levels if we know that the micropone is muted.
+    return;
+  } else {

[tommi (sloooow) - chröme, 2014/10/15 17:00:48]

nit: no need for else since there's an early return above

[henrika (OOO until Aug 14), 2014/10/16 09:58:00]

Done.

+    LogMicrophoneMuteResult(MICROPHONE_IS_NOT_MUTED);
+  }
+
+  log_string = base::StringPrintf(
       "AIC::OnData: average audio level=%.2f dBFS", level_dbfs);
   static const float kSilenceThresholdDBFS = -72.24719896f;
   if (level_dbfs < kSilenceThresholdDBFS)
@@ -598,20 +615,6 @@ void AudioInputController::DoLogAudioLevels(float level_dbfs,
   if (microphone_volume_percent < kLowLevelMicrophoneLevelPercent)
     log_string += " <=> low microphone level!";
   handler_->OnLog(this, log_string);
-
-  // Try to detect if the user has enabled hardware mute by pressing the mute
-  // button in audio settings for the selected microphone. The idea here is to
-  // detect when all input samples are zeros but the actual volume slider is
-  // larger than zero. It should correspond to a hardware mute state.
-  if (level_dbfs == -std::numeric_limits<float>::infinity() &&
-      microphone_volume_percent > 0) {
-    LogMicrophoneMuteResult(MICROPHONE_IS_MUTED);
-    log_string = base::StringPrintf(
-        "AIC::OnData: microphone is muted!");
-    handler_->OnLog(this, log_string);
-  } else {
-    LogMicrophoneMuteResult(MICROPHONE_IS_NOT_MUTED);
-  }
 #endif
 }