Add periodic logging of video stats.

webrtc/video_receive_stream.h

Index: webrtc/video_receive_stream.h
diff --git a/webrtc/video_receive_stream.h b/webrtc/video_receive_stream.h
index 410d5aff7f62adcec88ab455b79de43cd9b64303..a6499ef775df4fb06343851e3afd2f1a847132c7 100644
--- a/webrtc/video_receive_stream.h
+++ b/webrtc/video_receive_stream.h
@@ -46,6 +46,8 @@ class VideoReceiveStream {
   };
 
   struct Stats {
+    std::string ToString(int64_t time_ms) const;
+
     int network_frame_rate = 0;
     int decode_frame_rate = 0;
     int render_frame_rate = 0;
@@ -66,6 +68,9 @@ class VideoReceiveStream {
     int total_bitrate_bps = 0;
     int discarded_packets = 0;
 
+    int width = 0;
+    int height = 0;
+
     int sync_offset_ms = std::numeric_limits<int>::max();
 
     uint32_t ssrc = 0;