Add periodic logging of number of captured and dropped frames in VideoCaptureInput.

webrtc/video/vie_encoder.h

Index: webrtc/video/vie_encoder.h
diff --git a/webrtc/video/vie_encoder.h b/webrtc/video/vie_encoder.h
index 7408a53c1f59e2c0128cfcdcdb17473773d61f28..132b7dc773817c57dcb46106d30c404e5e2718cf 100644
--- a/webrtc/video/vie_encoder.h
+++ b/webrtc/video/vie_encoder.h
@@ -151,6 +151,10 @@ class ViEEncoder : public VideoCaptureInput,
   // Delta used for translating between NTP and internal timestamps.
   const int64_t delta_ntp_internal_ms_;
 
+  int64_t last_frame_log_ms_ GUARDED_BY(incoming_frame_race_checker_);
+  int captured_frame_count_ ACCESS_ON(&encoder_queue_);
+  int dropped_frame_count_ ACCESS_ON(&encoder_queue_);
+
   // All public methods are proxied to |encoder_queue_|. It must must be
   // destroyed first to make sure no tasks are run that use other members.
   rtc::TaskQueue encoder_queue_;