Experiment for the nack module.

webrtc/modules/video_coding/include/video_coding.h

Index: webrtc/modules/video_coding/include/video_coding.h
diff --git a/webrtc/modules/video_coding/include/video_coding.h b/webrtc/modules/video_coding/include/video_coding.h
index 6433f5628d044f9e88a015c252588b2673044e09..0c508b7739ab83f045f8d9a735de03310f13f7af 100644
--- a/webrtc/modules/video_coding/include/video_coding.h
+++ b/webrtc/modules/video_coding/include/video_coding.h
@@ -73,8 +73,21 @@ class VideoCodingModule : public Module {
       VideoEncoderRateObserver* encoder_rate_observer,
       VCMQMSettingsCallback* qm_settings_callback);
 
+  static VideoCodingModule* Create(
+      Clock* clock,
+      VideoEncoderRateObserver* encoder_rate_observer,
+      VCMQMSettingsCallback* qm_settings_callback,
+      NackSender* nack_sender,
+      KeyFrameRequestSender* keyframe_request_sender);
+
   static VideoCodingModule* Create(Clock* clock, EventFactory* event_factory);
 
+  static VideoCodingModule* Create(
+      Clock* clock,
+      EventFactory* event_factory,
+      NackSender* nack_sender,
+      KeyFrameRequestSender* keyframe_request_sender);
+
   // Get supported codec settings using codec type
   //
   // Input: