Surface the IntelligibilityEnhancer on MediaConstraints

webrtc/media/engine/webrtcvoiceengine.cc

Index: webrtc/media/engine/webrtcvoiceengine.cc
diff --git a/webrtc/media/engine/webrtcvoiceengine.cc b/webrtc/media/engine/webrtcvoiceengine.cc
index ed67ce84ba00cc520872b1a17e0ea8bdbb579160..4fcb200507e5072fd81ea7022f3b59c07f98aecc 100644
--- a/webrtc/media/engine/webrtcvoiceengine.cc
+++ b/webrtc/media/engine/webrtcvoiceengine.cc
@@ -843,6 +843,12 @@ bool WebRtcVoiceEngine::ApplyOptions(const AudioOptions& options_in) {
         new webrtc::ExperimentalNs(*experimental_ns_));
   }
 
+  const bool intelligibility_enhancer = adm()->IntelligibilityIsEnabled();

[the sun, 2016/05/06 09:00:15]

Is the idea to pass the option to enable IE via the ADM? Why not pass it through
the regular AudioOptions?

The ADM should be a wrapper for actual hardware resources.

[aluebs-webrtc, 2016/05/06 16:27:10]

Because I was pointed to the WebRtcAudioUtils API as to where this should be
enabled I found the AudioDevice to be the natural path, but I agree that it is
not intuitive. On the other hand I couldn't find a simple way to use the
AudioOptions with that API. But that is why I am asking for your feedback early.
I am happy to implement any other path you suggest.

+  LOG(LS_INFO) << "Intelligibility Enhancer is enabled? "
+               << intelligibility_enhancer;
+  config.Set<webrtc::Intelligibility>(
+      new webrtc::Intelligibility(intelligibility_enhancer));
+
   // We check audioproc for the benefit of tests, since FakeWebRtcVoiceEngine
   // returns NULL on audio_processing().
   webrtc::AudioProcessing* audioproc = voe_wrapper_->base()->audio_processing();