Add experimental noise suppression dummy API.

Add this flag to the voe_cmd_test.

R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/3879004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5134 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.cc b/webrtc/modules/audio_processing/audio_processing_impl.cc
index b33049e..2eb97bf 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.cc
+++ b/webrtc/modules/audio_processing/audio_processing_impl.cc
@@ -186,6 +186,10 @@
     (*it)->SetExtraOptions(config);
 }
 
+int AudioProcessingImpl::EnableExperimentalNs(bool enable) {
+  return kNoError;
+}
+
 int AudioProcessingImpl::set_sample_rate_hz(int rate) {
   CriticalSectionScoped crit_scoped(crit_);
   if (rate == sample_rate_hz_) {