stats: implement inbound-rtp totalProcessingDelay for video

https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-totalprocessingdelay

BUG=webrtc:13984

Change-Id: Ifd821bd8553add46218f09a11366096d62f5d09f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/259768
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36732}
diff --git a/api/stats/rtcstats_objects.h b/api/stats/rtcstats_objects.h
index a6d78f8..b22de2b 100644
--- a/api/stats/rtcstats_objects.h
+++ b/api/stats/rtcstats_objects.h
@@ -487,7 +487,6 @@
   RTCStatsMember<double> audio_level;
   RTCStatsMember<double> total_audio_energy;
   RTCStatsMember<double> total_samples_duration;
-  RTCStatsMember<int32_t> frames_received;
   // TODO(hbos): Collect and populate this value. https://bugs.webrtc.org/7065
   RTCStatsMember<double> round_trip_time;
   // TODO(hbos): Collect and populate this value. https://bugs.webrtc.org/7065
@@ -508,6 +507,8 @@
   RTCStatsMember<double> gap_loss_rate;
   // TODO(hbos): Collect and populate this value. https://bugs.webrtc.org/7065
   RTCStatsMember<double> gap_discard_rate;
+  // Stats below are only implemented or defined for video.
+  RTCStatsMember<int32_t> frames_received;
   RTCStatsMember<uint32_t> frame_width;
   RTCStatsMember<uint32_t> frame_height;
   RTCStatsMember<uint32_t> frame_bit_depth;
@@ -516,6 +517,7 @@
   RTCStatsMember<uint32_t> key_frames_decoded;
   RTCStatsMember<uint32_t> frames_dropped;
   RTCStatsMember<double> total_decode_time;
+  RTCStatsMember<double> total_processing_delay;
   RTCStatsMember<double> total_inter_frame_delay;
   RTCStatsMember<double> total_squared_inter_frame_delay;
   // https://henbos.github.io/webrtc-provisional-stats/#dom-rtcinboundrtpstreamstats-contenttype