Remove callback_cs_ in ViEEncoder.

webrtc/video_engine/vie_channel_group.h

Index: webrtc/video_engine/vie_channel_group.h
diff --git a/webrtc/video_engine/vie_channel_group.h b/webrtc/video_engine/vie_channel_group.h
index ec1708318d023880e971e7db488a444589531849..5208589c5768ff7412e5ab2833159fd41dc26eb6 100644
--- a/webrtc/video_engine/vie_channel_group.h
+++ b/webrtc/video_engine/vie_channel_group.h
@@ -26,10 +26,12 @@ class BitrateAllocator;
 class CallStats;
 class Config;
 class EncoderStateFeedback;
+class I420FrameCallback;
 class PacedSender;
 class PacketRouter;
 class ProcessThread;
 class RemoteBitrateEstimator;
+class SendStatisticsProxy;
 class ViEChannel;
 class ViEEncoder;
 class VieRemb;
@@ -45,6 +47,8 @@ class ChannelGroup : public BitrateObserver {
   ~ChannelGroup();
   bool CreateSendChannel(int channel_id,
                          Transport* transport,
+                         SendStatisticsProxy* stats_proxy,
+                         I420FrameCallback* pre_encode_callback,
                          int number_of_cores,
                          const std::vector<uint32_t>& ssrcs);
   bool CreateReceiveChannel(int channel_id,