Remove AudioDeviceObserver and make ADM not inherit from the Module interface.

modules/audio_device/mac/audio_device_mac.cc

Index: modules/audio_device/mac/audio_device_mac.cc
diff --git a/modules/audio_device/mac/audio_device_mac.cc b/modules/audio_device/mac/audio_device_mac.cc
index 01604ce6009be93ffe65344b471085006a444715..6ea199c40372544a12fd2c1640b798d94f62a120 100644
--- a/modules/audio_device/mac/audio_device_mac.cc
+++ b/modules/audio_device/mac/audio_device_mac.cc
@@ -144,10 +144,6 @@ AudioDeviceMac::AudioDeviceMac()
       _captureDelayUs(0),
       _renderDelayUs(0),
       _renderDelayOffsetSamples(0),
-      _playWarning(0),
-      _playError(0),
-      _recWarning(0),
-      _recError(0),
       _paCaptureBuffer(NULL),
       _paRenderBuffer(NULL),
       _captureBufSizeSamples(0),
@@ -340,11 +336,6 @@ AudioDeviceGeneric::InitStatus AudioDeviceMac::Init() {
     }
   }
 
-  _playWarning = 0;
-  _playError = 0;
-  _recWarning = 0;
-  _recError = 0;
-
   get_mic_volume_counter_ms_ = 0;
 
   _initialized = true;
@@ -1555,38 +1546,6 @@ bool AudioDeviceMac::Playing() const {
   return (_playing);
 }
 
-bool AudioDeviceMac::PlayoutWarning() const {
-  return (_playWarning > 0);
-}
-
-bool AudioDeviceMac::PlayoutError() const {
-  return (_playError > 0);
-}
-
-bool AudioDeviceMac::RecordingWarning() const {
-  return (_recWarning > 0);
-}
-
-bool AudioDeviceMac::RecordingError() const {
-  return (_recError > 0);
-}
-
-void AudioDeviceMac::ClearPlayoutWarning() {
-  _playWarning = 0;
-}
-
-void AudioDeviceMac::ClearPlayoutError() {
-  _playError = 0;
-}
-
-void AudioDeviceMac::ClearRecordingWarning() {
-  _recWarning = 0;
-}
-
-void AudioDeviceMac::ClearRecordingError() {
-  _recError = 0;
-}
-
 // ============================================================================
 //                                 Private Methods
 // ============================================================================
@@ -1999,10 +1958,6 @@ int32_t AudioDeviceMac::HandleDeviceChange() {
       LOG(LS_WARNING) << "Capture device is not alive (probably removed)";
       AtomicSet32(&_captureDeviceIsAlive, 0);
       _mixerManager.CloseMicrophone();
-      if (_recError == 1) {
-        LOG(LS_WARNING) << "pending recording error exists";
-      }
-      _recError = 1;  // triggers callback from module process thread
     } else if (err != noErr) {
       logCAMsg(rtc::LS_ERROR,
                "Error in AudioDeviceGetProperty()", (const char*)&err);
@@ -2022,10 +1977,6 @@ int32_t AudioDeviceMac::HandleDeviceChange() {
       LOG(LS_WARNING) << "Render device is not alive (probably removed)";
       AtomicSet32(&_renderDeviceIsAlive, 0);
       _mixerManager.CloseSpeaker();
-      if (_playError == 1) {
-        LOG(LS_WARNING) << "pending playout error exists";
-      }
-      _playError = 1;  // triggers callback from module process thread
     } else if (err != noErr) {
       logCAMsg(rtc::LS_ERROR,
                "Error in AudioDeviceGetProperty()", (const char*)&err);