Remove callback_cs_ in ViEEncoder.

webrtc/video_engine/encoder_state_feedback_unittest.cc

Index: webrtc/video_engine/encoder_state_feedback_unittest.cc
diff --git a/webrtc/video_engine/encoder_state_feedback_unittest.cc b/webrtc/video_engine/encoder_state_feedback_unittest.cc
index dc93266589a32e587e8628122f9ee55bc654abd7..b61fc56b4ce1195528e69feaf0c95329be9aee73 100644
--- a/webrtc/video_engine/encoder_state_feedback_unittest.cc
+++ b/webrtc/video_engine/encoder_state_feedback_unittest.cc
@@ -32,7 +32,7 @@ namespace webrtc {
 class MockVieEncoder : public ViEEncoder {
  public:
   explicit MockVieEncoder(ProcessThread* process_thread, PacedSender* pacer)
-      : ViEEncoder(1, 1, *process_thread, pacer, NULL) {}
+      : ViEEncoder(1, 1, process_thread, nullptr, nullptr, pacer, nullptr) {}
   ~MockVieEncoder() {}
 
   MOCK_METHOD1(OnReceivedIntraFrameRequest,