Added a kEchoCancellation constraint to turn off the audio processing.

content/renderer/media/media_stream_audio_processor.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_PROCESSOR_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_PROCESSOR_H_
 
 #include "base/atomicops.h"
 #include "base/platform_file.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "content/common/content_export.h"
-#include "content/public/common/media_stream_request.h"
 #include "content/renderer/media/webrtc_audio_device_impl.h"
 #include "media/base/audio_converter.h"
 #include "third_party/libjingle/source/talk/app/webrtc/mediastreaminterface.h"
 #include "third_party/webrtc/modules/audio_processing/include/audio_processing.h"
 #include "third_party/webrtc/modules/interface/module_common_types.h"
 
 namespace blink {
 class WebMediaConstraints;
 }
 
@@ skipping 20 matching lines @@
 // of 10 ms data chunk.
 class CONTENT_EXPORT MediaStreamAudioProcessor :
     NON_EXPORTED_BASE(public WebRtcPlayoutDataSource::Sink),
     NON_EXPORTED_BASE(public AudioProcessorInterface) {
  public:
   // |playout_data_source| is used to register this class as a sink to the
   // WebRtc playout data for processing AEC. If clients do not enable AEC,
   // |playout_data_source| won't be used.
   MediaStreamAudioProcessor(const blink::WebMediaConstraints& constraints,
                             int effects,
-                            MediaStreamType type,
                             WebRtcPlayoutDataSource* playout_data_source);
 
   // Called when format of the capture data has changed.
   // Called on the main render thread.  The caller is responsible for stopping
   // the capture thread before calling this method.
   // After this method, the capture thread will be changed to a new capture
   // thread.
   void OnCaptureFormatChanged(const media::AudioParameters& source_params);
 
   // Pushes capture data in |audio_source| to the internal FIFO.
@@ skipping 50 matching lines @@
                              int sample_rate,
                              int audio_delay_milliseconds) OVERRIDE;
   virtual void OnPlayoutDataSourceChanged() OVERRIDE;
 
   // webrtc::AudioProcessorInterface implementation.
   // This method is called on the libjingle thread.
   virtual void GetStats(AudioProcessorStats* stats) OVERRIDE;
 
   // Helper to initialize the WebRtc AudioProcessing.
   void InitializeAudioProcessingModule(
-      const blink::WebMediaConstraints& constraints, int effects,
-      MediaStreamType type);
+      const blink::WebMediaConstraints& constraints, int effects);
 
   // Helper to initialize the capture converter.
   void InitializeCaptureConverter(const media::AudioParameters& source_params);
 
   // Helper to initialize the render converter.
   void InitializeRenderConverterIfNeeded(int sample_rate,
                                          int number_of_channels,
                                          int frames_per_buffer);
 
   // Called by ProcessAndConsumeData().
@@ skipping 38 matching lines @@
   // Used to DCHECK that the destructor is called on the main render thread.
   base::ThreadChecker main_thread_checker_;
 
   // Used to DCHECK that some methods are called on the capture audio thread.
   base::ThreadChecker capture_thread_checker_;
 
   // Used to DCHECK that PushRenderData() is called on the render audio thread.
   base::ThreadChecker render_thread_checker_;
 
   // Flag to enable the stereo channels mirroring.
-  bool audio_mirroring_;
+  bool goog_audio_mirroring_;
 
   // Used by the typing detection.
   scoped_ptr<webrtc::TypingDetection> typing_detector_;
 
   // This flag is used to show the result of typing detection.
   // It can be accessed by the capture audio thread and by the libjingle thread

[perkj_chrome, 2014/04/11 11:45:04]

is this still true? is libjingle thread involved?

[no longer working on chromium, 2014/04/11 16:47:05]

Yes, by GetStats() from libjingle.

   // which calls GetStats().
-  base::subtle::Atomic32 typing_detected_;
+  base::subtle::Atomic32 goog_typing_detected_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_PROCESSOR_H_