Use vcm::VideoReceiver on the receive side.

BUG=
R=perkj@webrtc.org

Review URL: https://codereview.webrtc.org/1905983002 .

Cr-Commit-Position: refs/heads/master@{#12473}
diff --git a/webrtc/modules/video_coding/video_coding_impl.h b/webrtc/modules/video_coding/video_coding_impl.h
index e3184a8..f449632 100644
--- a/webrtc/modules/video_coding/video_coding_impl.h
+++ b/webrtc/modules/video_coding/video_coding_impl.h
@@ -128,7 +128,7 @@
   std::vector<FrameType> next_frame_types_ GUARDED_BY(params_crit_);
 };
 
-class VideoReceiver {
+class VideoReceiver : public Module {
  public:
   typedef VideoCodingModule::ReceiverRobustness ReceiverRobustness;
 
@@ -179,8 +179,8 @@
   int32_t SetReceiveChannelParameters(int64_t rtt);
   int32_t SetVideoProtection(VCMVideoProtection videoProtection, bool enable);
 
-  int64_t TimeUntilNextProcess();
-  void Process();
+  int64_t TimeUntilNextProcess() override;
+  void Process() override;
 
   void TriggerDecoderShutdown();