Add support for audio input mute detection on all platforms.

TBR=rkc@chromium.org
BUG=422275
TEST=Manual tests using DVLOGs to confirm valid microphone mute states.

Review URL: https://codereview.chromium.org/645923002

Cr-Commit-Position: refs/heads/master@{#299891}

27 files changed, 162 insertions, 33 deletions

diff --git a/components/copresence/mediums/audio/audio_recorder_unittest.cc b/components/copresence/mediums/audio/audio_recorder_unittest.cc
index df3f3e5..2c81213 100644
--- a/components/copresence/mediums/audio/audio_recorder_unittest.cc
+++ b/components/copresence/mediums/audio/audio_recorder_unittest.cc
@@ -47,6 +47,7 @@ class TestAudioInputStream : public media::AudioInputStream {
   virtual double GetVolume() override { return 1.0; }
   virtual void SetAutomaticGainControl(bool enabled) override {}
   virtual bool GetAutomaticGainControl() override { return true; }
+  virtual bool IsMuted() override { return false; }
 
  private:
   void SimulateRecording() {
diff --git a/content/browser/media/capture/web_contents_audio_input_stream.cc b/content/browser/media/capture/web_contents_audio_input_stream.cc
index ad4fd2f..cdf7eb9 100644
--- a/content/browser/media/capture/web_contents_audio_input_stream.cc
+++ b/content/browser/media/capture/web_contents_audio_input_stream.cc
@@ -391,4 +391,8 @@ bool WebContentsAudioInputStream::GetAutomaticGainControl() {
   return impl_->mixer_stream()->GetAutomaticGainControl();
 }
 
+bool WebContentsAudioInputStream::IsMuted() {
+  return false;
+}
+
 }  // namespace content
diff --git a/content/browser/media/capture/web_contents_audio_input_stream.h b/content/browser/media/capture/web_contents_audio_input_stream.h
index 2f34eed..a0468ff 100644
--- a/content/browser/media/capture/web_contents_audio_input_stream.h
+++ b/content/browser/media/capture/web_contents_audio_input_stream.h
@@ -46,6 +46,7 @@ class CONTENT_EXPORT WebContentsAudioInputStream
   virtual double GetVolume() override;
   virtual void SetAutomaticGainControl(bool enabled) override;
   virtual bool GetAutomaticGainControl() override;
+  virtual bool IsMuted() override;
 
   // Create a new audio mirroring session, or return NULL on error.  |device_id|
   // should be in the format accepted by
diff --git a/media/audio/alsa/alsa_input.cc b/media/audio/alsa/alsa_input.cc
index 0bc9f31..3c555a0 100644
--- a/media/audio/alsa/alsa_input.cc
+++ b/media/audio/alsa/alsa_input.cc
@@ -336,6 +336,10 @@ double AlsaPcmInputStream::GetVolume() {
   return static_cast<double>(current_volume);
 }
 
+bool AlsaPcmInputStream::IsMuted() {
+  return false;
+}
+
 void AlsaPcmInputStream::HandleError(const char* method, int error) {
   LOG(WARNING) << method << ": " << wrapper_->StrError(error);
   callback_->OnError(this);
diff --git a/media/audio/alsa/alsa_input.h b/media/audio/alsa/alsa_input.h
index adc2619..ef7cb2c 100644
--- a/media/audio/alsa/alsa_input.h
+++ b/media/audio/alsa/alsa_input.h
@@ -49,6 +49,7 @@ class AlsaPcmInputStream : public AgcAudioStream<AudioInputStream> {
   virtual double GetMaxVolume() override;
   virtual void SetVolume(double volume) override;
   virtual double GetVolume() override;
+  virtual bool IsMuted() override;
 
  private:
   // Logs the error and invokes any registered callbacks.
diff --git a/media/audio/android/audio_record_input.cc b/media/audio/android/audio_record_input.cc
index 3f19588..1dd6118 100644
--- a/media/audio/android/audio_record_input.cc
+++ b/media/audio/android/audio_record_input.cc
@@ -134,4 +134,9 @@ bool AudioRecordInputStream::GetAutomaticGainControl() {
   return false;
 }
 
+bool AudioRecordInputStream::IsMuted() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
 }  // namespace media
diff --git a/media/audio/android/audio_record_input.h b/media/audio/android/audio_record_input.h
index 198fd59..d4c4368 100644
--- a/media/audio/android/audio_record_input.h
+++ b/media/audio/android/audio_record_input.h
@@ -40,6 +40,7 @@ class MEDIA_EXPORT AudioRecordInputStream : public AudioInputStream {
   virtual double GetVolume() override;
   virtual void SetAutomaticGainControl(bool enabled) override;
   virtual bool GetAutomaticGainControl() override;
+  virtual bool IsMuted() override;
 
   static bool RegisterAudioRecordInput(JNIEnv* env);
 
diff --git a/media/audio/android/opensles_input.cc b/media/audio/android/opensles_input.cc
index 1ef3aac..d8e5f63 100644
--- a/media/audio/android/opensles_input.cc
+++ b/media/audio/android/opensles_input.cc
@@ -185,6 +185,11 @@ bool OpenSLESInputStream::GetAutomaticGainControl() {
   return false;
 }
 
+bool OpenSLESInputStream::IsMuted() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
 bool OpenSLESInputStream::CreateRecorder() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!engine_object_.Get());
diff --git a/media/audio/android/opensles_input.h b/media/audio/android/opensles_input.h
index 2998e53..ae62639 100644
--- a/media/audio/android/opensles_input.h
+++ b/media/audio/android/opensles_input.h
@@ -43,6 +43,7 @@ class OpenSLESInputStream : public AudioInputStream {
   virtual double GetVolume() override;
   virtual void SetAutomaticGainControl(bool enabled) override;
   virtual bool GetAutomaticGainControl() override;
+  virtual bool IsMuted() override;
 
  private:
   bool CreateRecorder();
diff --git a/media/audio/audio_input_controller.cc b/media/audio/audio_input_controller.cc
index 72239f0..3bd14f1 100644
--- a/media/audio/audio_input_controller.cc
+++ b/media/audio/audio_input_controller.cc
@@ -583,11 +583,24 @@ void AudioInputController::DoLogAudioLevels(float level_dbfs,
   if (!handler_)
     return;
 
+  // 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) {
+    LogMicrophoneMuteResult(MICROPHONE_IS_MUTED);
+    handler_->OnLog(this, "AIC::OnData: microphone is muted!");
+    // Return early if microphone is muted. No need to adding logs and UMA stats
+    // of audio levels if we know that the micropone is muted.
+    return;
+  }
+
+  LogMicrophoneMuteResult(MICROPHONE_IS_NOT_MUTED);
+
   std::string log_string = base::StringPrintf(
       "AIC::OnData: average audio level=%.2f dBFS", level_dbfs);
   static const float kSilenceThresholdDBFS = -72.24719896f;
   if (level_dbfs < kSilenceThresholdDBFS)
-    log_string += " <=> no audio input!";
+    log_string += " <=> low audio input level!";
   handler_->OnLog(this, log_string);
 
   UpdateSilenceState(level_dbfs < kSilenceThresholdDBFS);
@@ -598,20 +611,6 @@ 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
 }
 
diff --git a/media/audio/audio_io.h b/media/audio/audio_io.h
index 105e32e..3add053 100644
--- a/media/audio/audio_io.h
+++ b/media/audio/audio_io.h
@@ -164,6 +164,9 @@ class MEDIA_EXPORT AudioInputStream {
 
   // Returns the Automatic Gain Control (AGC) state.
   virtual bool GetAutomaticGainControl() = 0;
+
+  // Returns the current muting state for the microphone.
+  virtual bool IsMuted() = 0;
 };
 
 }  // namespace media
diff --git a/media/audio/cras/cras_input.cc b/media/audio/cras/cras_input.cc
index 0b86446..3fae8df 100644
--- a/media/audio/cras/cras_input.cc
+++ b/media/audio/cras/cras_input.cc
@@ -301,6 +301,10 @@ double CrasInputStream::GetVolume() {
   return GetVolumeRatioFromDecibels(dB);
 }
 
+bool CrasInputStream::IsMuted() {
+  return false;
+}
+
 double CrasInputStream::GetVolumeRatioFromDecibels(double dB) const {
   return pow(10, dB / 20.0);
 }
diff --git a/media/audio/cras/cras_input.h b/media/audio/cras/cras_input.h
index 4f5614d..f290f1e 100644
--- a/media/audio/cras/cras_input.h
+++ b/media/audio/cras/cras_input.h
@@ -40,6 +40,7 @@ class CrasInputStream : public AgcAudioStream<AudioInputStream> {
   virtual double GetMaxVolume() override;
   virtual void SetVolume(double volume) override;
   virtual double GetVolume() override;
+  virtual bool IsMuted() override;
 
  private:
   // Handles requests to get samples from the provided buffer.  This will be
diff --git a/media/audio/fake_audio_input_stream.cc b/media/audio/fake_audio_input_stream.cc
index 74ac579..157d397 100644
--- a/media/audio/fake_audio_input_stream.cc
+++ b/media/audio/fake_audio_input_stream.cc
@@ -203,6 +203,11 @@ double FakeAudioInputStream::GetVolume() {
   return 1.0;
 }
 
+bool FakeAudioInputStream::IsMuted() {
+  DCHECK(audio_manager_->GetTaskRunner()->BelongsToCurrentThread());
+  return false;
+}
+
 void FakeAudioInputStream::SetAutomaticGainControl(bool enabled) {}
 
 bool FakeAudioInputStream::GetAutomaticGainControl() {
diff --git a/media/audio/fake_audio_input_stream.h b/media/audio/fake_audio_input_stream.h
index db00c2e..dba6aaa 100644
--- a/media/audio/fake_audio_input_stream.h
+++ b/media/audio/fake_audio_input_stream.h
@@ -34,6 +34,7 @@ class MEDIA_EXPORT FakeAudioInputStream
   virtual double GetMaxVolume() override;
   virtual void SetVolume(double volume) override;
   virtual double GetVolume() override;
+  virtual bool IsMuted() override;
   virtual void SetAutomaticGainControl(bool enabled) override;
   virtual bool GetAutomaticGainControl() override;
 
diff --git a/media/audio/mac/audio_input_mac.cc b/media/audio/mac/audio_input_mac.cc
index b7f6e17..af5d9bc 100644
--- a/media/audio/mac/audio_input_mac.cc
+++ b/media/audio/mac/audio_input_mac.cc
@@ -136,6 +136,11 @@ double PCMQueueInAudioInputStream::GetVolume() {
   return 0.0;
 }
 
+bool PCMQueueInAudioInputStream::IsMuted() {
+  NOTREACHED() << "Only supported for low-latency mode.";
+  return false;
+}
+
 void PCMQueueInAudioInputStream::SetAutomaticGainControl(bool enabled) {
   NOTREACHED() << "Only supported for low-latency mode.";
 }
diff --git a/media/audio/mac/audio_input_mac.h b/media/audio/mac/audio_input_mac.h
index 37afcee..6c1b4a14f 100644
--- a/media/audio/mac/audio_input_mac.h
+++ b/media/audio/mac/audio_input_mac.h
@@ -38,6 +38,7 @@ class PCMQueueInAudioInputStream : public AudioInputStream {
   virtual double GetVolume() override;
   virtual void SetAutomaticGainControl(bool enabled) override;
   virtual bool GetAutomaticGainControl() override;
+  virtual bool IsMuted() override;
 
  private:
   // Issue the OnError to |callback_|;
diff --git a/media/audio/mac/audio_low_latency_input_mac.cc b/media/audio/mac/audio_low_latency_input_mac.cc
index 1baa09f..2b2ce00 100644
--- a/media/audio/mac/audio_low_latency_input_mac.cc
+++ b/media/audio/mac/audio_low_latency_input_mac.cc
@@ -451,6 +451,29 @@ double AUAudioInputStream::GetVolume() {
   return 0.0;
 }
 
+bool AUAudioInputStream::IsMuted() {
+  // Verify that we have a valid device.
+  DCHECK_NE(input_device_id_, kAudioObjectUnknown) << "Device ID is unknown";
+
+  AudioObjectPropertyAddress property_address = {
+    kAudioDevicePropertyMute,
+    kAudioDevicePropertyScopeInput,
+    kAudioObjectPropertyElementMaster
+  };
+
+  if (!AudioObjectHasProperty(input_device_id_, &property_address)) {
+    DLOG(ERROR) << "Device does not support checking master mute state";
+    return false;
+  }
+
+  UInt32 muted = 0;
+  UInt32 size = sizeof(muted);
+  OSStatus result = AudioObjectGetPropertyData(
+      input_device_id_, &property_address, 0, NULL, &size, &muted);
+  DLOG_IF(WARNING, result != noErr) << "Failed to get mute state";
+  return result == noErr && muted != 0;
+}
+
 // AUHAL AudioDeviceOutput unit callback
 OSStatus AUAudioInputStream::InputProc(void* user_data,
                                        AudioUnitRenderActionFlags* flags,
diff --git a/media/audio/mac/audio_low_latency_input_mac.h b/media/audio/mac/audio_low_latency_input_mac.h
index 623cf1d..b3950ffd 100644
--- a/media/audio/mac/audio_low_latency_input_mac.h
+++ b/media/audio/mac/audio_low_latency_input_mac.h
@@ -72,6 +72,7 @@ class AUAudioInputStream : public AgcAudioStream<AudioInputStream> {
   virtual double GetMaxVolume() override;
   virtual void SetVolume(double volume) override;
   virtual double GetVolume() override;
+  virtual bool IsMuted() override;
 
   // Returns the current hardware sample rate for the default input device.
   MEDIA_EXPORT static int HardwareSampleRate();
diff --git a/media/audio/pulse/pulse_input.cc b/media/audio/pulse/pulse_input.cc
index 14ef242..7e2ca22 100644
--- a/media/audio/pulse/pulse_input.cc
+++ b/media/audio/pulse/pulse_input.cc
@@ -4,8 +4,6 @@
 
 #include "media/audio/pulse/pulse_input.h"
 
-#include <pulse/pulseaudio.h>
-
 #include "base/logging.h"
 #include "media/audio/pulse/audio_manager_pulse.h"
 #include "media/audio/pulse/pulse_util.h"
@@ -30,6 +28,7 @@ PulseAudioInputStream::PulseAudioInputStream(AudioManagerPulse* audio_manager,
       channels_(0),
       volume_(0.0),
       stream_started_(false),
+      muted_(false),
       fifo_(params.channels(),
             params.frames_per_buffer(),
             kNumberOfBlocksBufferInFifo),
@@ -185,20 +184,17 @@ double PulseAudioInputStream::GetVolume() {
     // Return zero and the callback will asynchronously update the |volume_|.
     return 0.0;
   } else {
-    // Called by other thread, put an AutoPulseLock and wait for the operation.
-    AutoPulseLock auto_lock(pa_mainloop_);
-    if (!handle_)
-      return 0.0;
-
-    size_t index = pa_stream_get_device_index(handle_);
-    pa_operation* operation = pa_context_get_source_info_by_index(
-        pa_context_, index, &VolumeCallback, this);
-    WaitForOperationCompletion(pa_mainloop_, operation);
-
+    GetSourceInformation(&VolumeCallback);
     return volume_;
   }
 }
 
+bool PulseAudioInputStream::IsMuted() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  GetSourceInformation(&MuteCallback);
+  return muted_;
+}
+
 // static, used by pa_stream_set_read_callback.
 void PulseAudioInputStream::ReadCallback(pa_stream* handle,
                                          size_t length,
@@ -236,11 +232,32 @@ void PulseAudioInputStream::VolumeCallback(pa_context* context,
   stream->volume_ = static_cast<double>(volume);
 }
 
+// static, used by pa_context_get_source_info_by_index.
+void PulseAudioInputStream::MuteCallback(pa_context* context,
+                                         const pa_source_info* info,
+                                         int error,
+                                         void* user_data) {
+  // Runs on PulseAudio callback thread. It might be possible to make this
+  // method more thread safe by passing a struct (or pair) of a local copy of
+  // |pa_mainloop_| and |muted_| instead.
+  PulseAudioInputStream* stream =
+      reinterpret_cast<PulseAudioInputStream*>(user_data);
+
+  // Avoid infinite wait loop in case of error.
+  if (error) {
+    pa_threaded_mainloop_signal(stream->pa_mainloop_, 0);
+    return;
+  }
+
+  stream->muted_ = info->mute != 0;
+}
+
 // static, used by pa_stream_set_state_callback.
 void PulseAudioInputStream::StreamNotifyCallback(pa_stream* s,
                                                  void* user_data) {
   PulseAudioInputStream* stream =
       reinterpret_cast<PulseAudioInputStream*>(user_data);
+
   if (s && stream->callback_ &&
       pa_stream_get_state(s) == PA_STREAM_FAILED) {
     stream->callback_->OnError(stream);
@@ -301,4 +318,16 @@ void PulseAudioInputStream::ReadData() {
   pa_threaded_mainloop_signal(pa_mainloop_, 0);
 }
 
+bool PulseAudioInputStream::GetSourceInformation(pa_source_info_cb_t callback) {
+  AutoPulseLock auto_lock(pa_mainloop_);
+  if (!handle_)
+    return false;
+
+  size_t index = pa_stream_get_device_index(handle_);
+  pa_operation* operation =
+      pa_context_get_source_info_by_index(pa_context_, index, callback, this);
+  WaitForOperationCompletion(pa_mainloop_, operation);
+  return true;
+}
+
 }  // namespace media
diff --git a/media/audio/pulse/pulse_input.h b/media/audio/pulse/pulse_input.h
index 60acf2f..dd42b31 100644
--- a/media/audio/pulse/pulse_input.h
+++ b/media/audio/pulse/pulse_input.h
@@ -5,6 +5,7 @@
 #ifndef MEDIA_AUDIO_PULSE_PULSE_INPUT_H_
 #define MEDIA_AUDIO_PULSE_PULSE_INPUT_H_
 
+#include <pulse/pulseaudio.h>
 #include <string>
 
 #include "base/threading/thread_checker.h"
@@ -14,11 +15,6 @@
 #include "media/audio/audio_parameters.h"
 #include "media/base/audio_block_fifo.h"
 
-struct pa_context;
-struct pa_source_info;
-struct pa_stream;
-struct pa_threaded_mainloop;
-
 namespace media {
 
 class AudioManagerPulse;
@@ -41,6 +37,7 @@ class PulseAudioInputStream : public AgcAudioStream<AudioInputStream> {
   virtual double GetMaxVolume() override;
   virtual void SetVolume(double volume) override;
   virtual double GetVolume() override;
+  virtual bool IsMuted() override;
 
  private:
   // PulseAudio Callbacks.
@@ -48,10 +45,17 @@ class PulseAudioInputStream : public AgcAudioStream<AudioInputStream> {
   static void StreamNotifyCallback(pa_stream* stream, void* user_data);
   static void VolumeCallback(pa_context* context, const pa_source_info* info,
                              int error, void* user_data);
+  static void MuteCallback(pa_context* context,
+                           const pa_source_info* info,
+                           int error,
+                           void* user_data);
 
   // Helper for the ReadCallback.
   void ReadData();
 
+  // Utility method used by GetVolume() and IsMuted().
+  bool GetSourceInformation(pa_source_info_cb_t callback);
+
   AudioManagerPulse* audio_manager_;
   AudioInputCallback* callback_;
   std::string device_name_;
@@ -60,6 +64,10 @@ class PulseAudioInputStream : public AgcAudioStream<AudioInputStream> {
   double volume_;
   bool stream_started_;
 
+  // Set to true in IsMuted() if user has muted the selected microphone in the
+  // sound settings UI.
+  bool muted_;
+
   // Holds the data from the OS.
   AudioBlockFifo fifo_;
 
diff --git a/media/audio/virtual_audio_input_stream.cc b/media/audio/virtual_audio_input_stream.cc
index c832a82..6d1189e 100644
--- a/media/audio/virtual_audio_input_stream.cc
+++ b/media/audio/virtual_audio_input_stream.cc
@@ -173,4 +173,8 @@ bool VirtualAudioInputStream::GetAutomaticGainControl() {
   return false;
 }
 
+bool VirtualAudioInputStream::IsMuted() {
+  return false;
+}
+
 }  // namespace media
diff --git a/media/audio/virtual_audio_input_stream.h b/media/audio/virtual_audio_input_stream.h
index 88c92ea..b33dadd 100644
--- a/media/audio/virtual_audio_input_stream.h
+++ b/media/audio/virtual_audio_input_stream.h
@@ -56,6 +56,7 @@ class MEDIA_EXPORT VirtualAudioInputStream : public AudioInputStream {
   virtual double GetVolume() override;
   virtual void SetAutomaticGainControl(bool enabled) override;
   virtual bool GetAutomaticGainControl() override;
+  virtual bool IsMuted() override;
 
   // Attaches a VirtualAudioOutputStream to be used as input. This
   // VirtualAudioInputStream must outlive all attached streams, so any attached
diff --git a/media/audio/win/audio_low_latency_input_win.cc b/media/audio/win/audio_low_latency_input_win.cc
index 9fe061b..8df8620 100644
--- a/media/audio/win/audio_low_latency_input_win.cc
+++ b/media/audio/win/audio_low_latency_input_win.cc
@@ -253,7 +253,7 @@ void WASAPIAudioInputStream::SetVolume(double volume) {
 }
 
 double WASAPIAudioInputStream::GetVolume() {
-  DLOG_IF(ERROR, !opened_) << "Open() has not been called successfully";
+  DCHECK(opened_) << "Open() has not been called successfully";
   if (!opened_)
     return 0.0;
 
@@ -265,6 +265,20 @@ double WASAPIAudioInputStream::GetVolume() {
   return static_cast<double>(level);
 }
 
+bool WASAPIAudioInputStream::IsMuted() {
+  DCHECK(opened_) << "Open() has not been called successfully";
+  DCHECK(CalledOnValidThread());
+  if (!opened_)
+    return false;
+
+  // Retrieves the current muting state for the audio session.
+  BOOL is_muted = FALSE;
+  HRESULT hr = simple_audio_volume_->GetMute(&is_muted);
+  DLOG_IF(WARNING, FAILED(hr)) << "Failed to get input master volume.";
+
+  return is_muted != FALSE;
+}
+
 // static
 AudioParameters WASAPIAudioInputStream::GetInputStreamParameters(
     const std::string& device_id) {
diff --git a/media/audio/win/audio_low_latency_input_win.h b/media/audio/win/audio_low_latency_input_win.h
index 51feac7..e933a44 100644
--- a/media/audio/win/audio_low_latency_input_win.h
+++ b/media/audio/win/audio_low_latency_input_win.h
@@ -102,6 +102,7 @@ class MEDIA_EXPORT WASAPIAudioInputStream
   virtual double GetMaxVolume() override;
   virtual void SetVolume(double volume) override;
   virtual double GetVolume() override;
+  virtual bool IsMuted() override;
 
   bool started() const { return started_; }
 
diff --git a/media/audio/win/wavein_input_win.cc b/media/audio/win/wavein_input_win.cc
index e96a877..72c5841 100644
--- a/media/audio/win/wavein_input_win.cc
+++ b/media/audio/win/wavein_input_win.cc
@@ -226,6 +226,11 @@ bool PCMWaveInAudioInputStream::GetAutomaticGainControl() {
   return false;
 }
 
+bool PCMWaveInAudioInputStream::IsMuted() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
 void PCMWaveInAudioInputStream::HandleError(MMRESULT error) {
   DLOG(WARNING) << "PCMWaveInAudio error " << error;
   if (callback_)
diff --git a/media/audio/win/wavein_input_win.h b/media/audio/win/wavein_input_win.h
index c587ed6..8c22c9b 100644
--- a/media/audio/win/wavein_input_win.h
+++ b/media/audio/win/wavein_input_win.h
@@ -45,6 +45,7 @@ class PCMWaveInAudioInputStream : public AudioInputStream {
   virtual double GetVolume() override;
   virtual void SetAutomaticGainControl(bool enabled) override;
   virtual bool GetAutomaticGainControl() override;
+  virtual bool IsMuted() override;
 
  private:
   enum State {