MediaStream audio sourcing: Bypass audio processing for non-WebRTC cases.

content/renderer/media/media_stream_audio_processor.cc

Index: content/renderer/media/media_stream_audio_processor.cc
diff --git a/content/renderer/media/media_stream_audio_processor.cc b/content/renderer/media/media_stream_audio_processor.cc
index 2df3604977c8daf5c3695af544c2831ac073210d..dccdf7703fd4c81832b12ed9469279671c593fe3 100644
--- a/content/renderer/media/media_stream_audio_processor.cc
+++ b/content/renderer/media/media_stream_audio_processor.cc
@@ -428,6 +428,48 @@ void MediaStreamAudioProcessor::OnIpcClosing() {
   aec_dump_message_filter_ = NULL;
 }
 
+// static
+bool MediaStreamAudioProcessor::ShouldRouteAudioThroughProcessor(
+    const blink::WebMediaConstraints& constraints,
+    int effects_flags) {
+  // Note: This method should by kept in-sync with any changes to the logic in
+  // MediaStreamAudioProcessor::InitializeAudioProcessingModule().
+
+  const MediaAudioConstraints audio_constraints(constraints, effects_flags);
+
+  if (audio_constraints.GetProperty(MediaAudioConstraints::kGoogAudioMirroring))
+    return true;
+
+#if !defined(OS_IOS)
+  if (audio_constraints.GetEchoCancellationProperty() ||
+      audio_constraints.GetProperty(
+          MediaAudioConstraints::kGoogAutoGainControl)) {
+    return true;
+  }
+#endif
+
+#if !defined(OS_IOS) && !defined(OS_ANDROID)
+  if (audio_constraints.GetProperty(
+          MediaAudioConstraints::kGoogExperimentalEchoCancellation) ||
+      audio_constraints.GetProperty(
+          MediaAudioConstraints::kGoogTypingNoiseDetection)) {
+    return true;
+  }
+#endif
+
+  if (audio_constraints.GetProperty(
+          MediaAudioConstraints::kGoogNoiseSuppression) ||
+      audio_constraints.GetProperty(
+          MediaAudioConstraints::kGoogExperimentalNoiseSuppression) ||
+      audio_constraints.GetProperty(MediaAudioConstraints::kGoogBeamforming) ||
+      audio_constraints.GetProperty(
+          MediaAudioConstraints::kGoogHighpassFilter)) {
+    return true;
+  }
+
+  return false;
+}
+
 void MediaStreamAudioProcessor::OnPlayoutData(media::AudioBus* audio_bus,
                                               int sample_rate,
                                               int audio_delay_milliseconds) {
@@ -522,8 +564,16 @@ void MediaStreamAudioProcessor::InitializeAudioProcessingModule(
   if (!echo_cancellation && !goog_experimental_aec && !goog_ns &&
       !goog_high_pass_filter && !goog_typing_detection &&
       !goog_agc && !goog_experimental_ns && !goog_beamforming) {
+    // Ensure ShouldRouteAudioThroughProcessor() is kept in-sync with all of the
+    // above logic.
+    DCHECK_EQ(audio_mirroring_, ShouldRouteAudioThroughProcessor(
+                                    constraints, input_params.effects));
     RecordProcessingState(AUDIO_PROCESSING_DISABLED);
     return;
+  } else {
+    // Ensure ShouldRouteAudioThroughProcessor() is kept in-sync with all of the
+    // above logic.
+    DCHECK(ShouldRouteAudioThroughProcessor(constraints, input_params.effects));
   }
 
   // Experimental options provided at creation.