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 145 matching lines @@
       device_info_.device.matched_output.sample_rate,
       device_info_.device.matched_output.frames_per_buffer,
       device_info_.device.input.effects));
 
   if (render_view_id_ == -1) {
     // Return true here to allow injecting a new source via
     // SetCapturerSourceForTesting() at a later state.
     return true;
   }
 
+  MediaAudioConstraints audio_constraints(constraints_,
+                                          device_info_.device.input.effects);
+  if (!audio_constraints.IsValid()) {

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

Per, after thinking a bit more, I am not sure if we should check the mandatory
constraints. For example, if we are deprecating some of our goog* constraints,
and remove it from our code base, then our users putting those constraints to
mandatory filed will fail on AddTrack.

[perkj_chrome, 2014/04/14 12:15:19]

If they are mandatory, we should fail. But if that is not the behavior we
currently have with the goog prefixed, you can consider filtering them out and
only fail if its  a w3c defined constraint. 

+    DLOG(ERROR) << "Constraints contain invalid mandatory keys";
+    return false;
+  }
+
   media::ChannelLayout channel_layout = static_cast<media::ChannelLayout>(
       device_info_.device.input.channel_layout);
   DVLOG(1) << "Audio input hardware channel layout: " << channel_layout;
   UMA_HISTOGRAM_ENUMERATION("WebRTC.AudioInputChannelLayout",
                             channel_layout, media::CHANNEL_LAYOUT_MAX + 1);
 
   // Verify that the reported input channel configuration is supported.
   if (channel_layout != media::CHANNEL_LAYOUT_MONO &&
       channel_layout != media::CHANNEL_LAYOUT_STEREO) {
     DLOG(ERROR) << channel_layout
@@ skipping 37 matching lines @@
 }
 
 WebRtcAudioCapturer::WebRtcAudioCapturer(
     int render_view_id,
     const StreamDeviceInfo& device_info,
     const blink::WebMediaConstraints& constraints,
     WebRtcAudioDeviceImpl* audio_device)
     : constraints_(constraints),
       audio_processor_(
           new talk_base::RefCountedObject<MediaStreamAudioProcessor>(
-              constraints, device_info.device.input.effects,
-              device_info.device.type, audio_device)),
+              constraints, device_info.device.input.effects, audio_device)),
       running_(false),
       render_view_id_(render_view_id),
       device_info_(device_info),
       volume_(0),
       peer_connection_mode_(false),
       key_pressed_(false),
       need_audio_processing_(false),
       audio_device_(audio_device),
       audio_power_monitor_(
           device_info_.device.input.sample_rate,
@@ skipping 78 matching lines @@
   media::AudioParameters params(media::AudioParameters::AUDIO_PCM_LOW_LATENCY,
                                 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);
+    MediaAudioConstraints audio_constraints(constraints_,
+                                            device_info_.device.input.effects);
+    need_audio_processing_ = audio_constraints.NeedsAudioProcessing();
     // Notify all tracks about the new format.
     tracks_.TagAll();
   }
 
   if (source.get())
     source->Initialize(params, this, session_id());
 
   if (restart_source)
     Start();
 }
@@ skipping 270 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