Clean up the media stream audio track code

content/renderer/media/webrtc_audio_device_impl.cc

Index: content/renderer/media/webrtc_audio_device_impl.cc
diff --git a/content/renderer/media/webrtc_audio_device_impl.cc b/content/renderer/media/webrtc_audio_device_impl.cc
index 2e6eed649d5b7c4054565870da03792248bd45c0..064babb7ef0279bdbde385f1a99a61d544807a7e 100644
--- a/content/renderer/media/webrtc_audio_device_impl.cc
+++ b/content/renderer/media/webrtc_audio_device_impl.cc
@@ -23,14 +23,11 @@ namespace content {
 WebRtcAudioDeviceImpl::WebRtcAudioDeviceImpl()
     : ref_count_(0),
       audio_transport_callback_(NULL),
-      input_delay_ms_(0),
       output_delay_ms_(0),
       initialized_(false),
       playing_(false),
       recording_(false),
-      microphone_volume_(0),
-      is_audio_track_processing_enabled_(
-          MediaStreamAudioProcessor::IsAudioTrackProcessingEnabled()) {
+      microphone_volume_(0) {
   DVLOG(1) << "WebRtcAudioDeviceImpl::WebRtcAudioDeviceImpl()";
 }
 
@@ -53,76 +50,6 @@ int32_t WebRtcAudioDeviceImpl::Release() {
   }
   return ret;
 }
-int WebRtcAudioDeviceImpl::OnData(const int16* audio_data,
-                                  int sample_rate,
-                                  int number_of_channels,
-                                  int number_of_frames,
-                                  const std::vector<int>& channels,
-                                  int audio_delay_milliseconds,
-                                  int current_volume,
-                                  bool need_audio_processing,
-                                  bool key_pressed) {
-  int total_delay_ms = 0;
-  {
-    base::AutoLock auto_lock(lock_);
-    // Return immediately when not recording or |channels| is empty.
-    // See crbug.com/274017: renderer crash dereferencing invalid channels[0].
-    if (!recording_ || channels.empty())
-      return 0;
-
-    // Store the reported audio delay locally.
-    input_delay_ms_ = audio_delay_milliseconds;
-    total_delay_ms = input_delay_ms_ + output_delay_ms_;
-    DVLOG(2) << "total delay: " << input_delay_ms_ + output_delay_ms_;
-  }
-
-  // Write audio frames in blocks of 10 milliseconds to the registered
-  // webrtc::AudioTransport sink. Keep writing until our internal byte
-  // buffer is empty.
-  const int16* audio_buffer = audio_data;
-  const int frames_per_10_ms = (sample_rate / 100);
-  CHECK_EQ(number_of_frames % frames_per_10_ms, 0);
-  int accumulated_audio_frames = 0;
-  uint32_t new_volume = 0;
-
-  // The lock here is to protect a race in the resampler inside webrtc when
-  // there are more than one input stream calling OnData(), which can happen
-  // when the users setup two getUserMedia, one for the microphone, another
-  // for WebAudio. Currently we don't have a better way to fix it except for
-  // adding a lock here to sequence the call.
-  // TODO(xians): Remove this workaround after we move the
-  // webrtc::AudioProcessing module to Chrome. See http://crbug/264611 for
-  // details.
-  base::AutoLock auto_lock(capture_callback_lock_);
-  while (accumulated_audio_frames < number_of_frames) {
-    // Deliver 10ms of recorded 16-bit linear PCM audio.
-    int new_mic_level = audio_transport_callback_->OnDataAvailable(
-        &channels[0],
-        channels.size(),
-        audio_buffer,
-        sample_rate,
-        number_of_channels,
-        frames_per_10_ms,
-        total_delay_ms,
-        current_volume,
-        key_pressed,
-        need_audio_processing);
-
-    accumulated_audio_frames += frames_per_10_ms;
-    audio_buffer += frames_per_10_ms * number_of_channels;
-
-    // The latest non-zero new microphone level will be returned.
-    if (new_mic_level)
-      new_volume = new_mic_level;
-  }
-
-  return new_volume;
-}
-
-void WebRtcAudioDeviceImpl::OnSetFormat(
-    const media::AudioParameters& params) {
-  DVLOG(1) << "WebRtcAudioDeviceImpl::OnSetFormat()";
-}
 
 void WebRtcAudioDeviceImpl::RenderData(media::AudioBus* audio_bus,
                                        int sample_rate,
@@ -146,40 +73,21 @@ void WebRtcAudioDeviceImpl::RenderData(media::AudioBus* audio_bus,
   // Get audio frames in blocks of 10 milliseconds from the registered
   // webrtc::AudioTransport source. Keep reading until our internal buffer
   // is full.
-  uint32_t num_audio_frames = 0;
   int accumulated_audio_frames = 0;
   int16* audio_data = &render_buffer_[0];
   while (accumulated_audio_frames < audio_bus->frames()) {
     // Get 10ms and append output to temporary byte buffer.
     int64_t elapsed_time_ms = -1;
     int64_t ntp_time_ms = -1;
-    if (is_audio_track_processing_enabled_) {
-      // When audio processing is enabled in the audio track, we use
-      // PullRenderData() instead of NeedMorePlayData() to avoid passing the
-      // render data to the APM in WebRTC as reference signal for echo
-      // cancellation.
-      static const int kBitsPerByte = 8;
-      audio_transport_callback_->PullRenderData(bytes_per_sample * kBitsPerByte,
-                                                sample_rate,
-                                                audio_bus->channels(),
-                                                frames_per_10_ms,
-                                                audio_data,
-                                                &elapsed_time_ms,
-                                                &ntp_time_ms);
-      accumulated_audio_frames += frames_per_10_ms;
-    } else {
-      // TODO(xians): Remove the following code after the APM in WebRTC is
-      // deprecated.
-      audio_transport_callback_->NeedMorePlayData(frames_per_10_ms,
-                                                  bytes_per_sample,
-                                                  audio_bus->channels(),
-                                                  sample_rate,
-                                                  audio_data,
-                                                  num_audio_frames,
-                                                  &elapsed_time_ms,
-                                                  &ntp_time_ms);
-      accumulated_audio_frames += num_audio_frames;
-    }
+    static const int kBitsPerByte = 8;
+    audio_transport_callback_->PullRenderData(bytes_per_sample * kBitsPerByte,
+                                              sample_rate,
+                                              audio_bus->channels(),
+                                              frames_per_10_ms,
+                                              audio_data,
+                                              &elapsed_time_ms,
+                                              &ntp_time_ms);
+    accumulated_audio_frames += frames_per_10_ms;
     if (elapsed_time_ms >= 0) {
       *current_time = base::TimeDelta::FromMilliseconds(elapsed_time_ms);
     }
@@ -425,9 +333,10 @@ int32_t WebRtcAudioDeviceImpl::PlayoutDelay(uint16_t* delay_ms) const {
 }
 
 int32_t WebRtcAudioDeviceImpl::RecordingDelay(uint16_t* delay_ms) const {
-  base::AutoLock auto_lock(lock_);
-  *delay_ms = static_cast<uint16_t>(input_delay_ms_);
-  return 0;
+  // There is no way to report a correct delay value to WebRTC since there
+  // might be multiple WebRtcAudioCapturer instances.
+  NOTREACHED();
+  return -1;
 }
 
 int32_t WebRtcAudioDeviceImpl::RecordingSampleRate(