Added a kEchoCancellation constraint to turn off the audio processing.

content/renderer/media/webrtc_audio_capturer.cc

 // Copyright (c) 2012 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.
 
 #include "content/renderer/media/webrtc_audio_capturer.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
@@ skipping 292 matching lines @@
                                 channel_layout, 0, sample_rate,
                                 16, buffer_size,
                                 device_info_.device.input.effects);
 
   {
     base::AutoLock auto_lock(lock_);
     // Notify the |audio_processor_| of the new format.
     audio_processor_->OnCaptureFormatChanged(params);
 
     need_audio_processing_ = NeedsAudioProcessing(
-        constraints_, device_info_.device.input.effects);
+        constraints_, device_info_.device.input.effects,
+        device_info_.device.type);
     // Notify all tracks about the new format.
     tracks_.TagAll();
   }
 
   if (source.get())
     source->Initialize(params, this, session_id());
 
   if (restart_source)
     Start();
 }
@@ skipping 256 matching lines @@
   DCHECK_NE(aec_dump_file, base::kInvalidPlatformFileValue);
   audio_processor_->StartAecDump(aec_dump_file);
 }
 
 void WebRtcAudioCapturer::StopAecDump() {
   DCHECK(thread_checker_.CalledOnValidThread());
   audio_processor_->StopAecDump();
 }
 
 }  // namespace content