Reland "Fix GetStats bytesSent/Received, wireup headerBytesSent/Received"

This is a reland of fbde32e596f06893d6dda13eb7d29f4c251cf08b

The chromium problem should be fixed with
https://chromium-review.googlesource.com/c/chromium/src/+/1862437

Original change's description:
> Fix GetStats bytesSent/Received, wireup headerBytesSent/Received
>
> Changes the standard GetStats, legacy GetStats unchanged.
>
> Bug: webrtc:10525
> Change-Id: Ie10fe8079f1d8b4cc6bbe513f6a2fc91477b5441
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/156084
> Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
> Reviewed-by: Henrik Boström <hbos@webrtc.org>
> Reviewed-by: Harald Alvestrand <hta@webrtc.org>
> Commit-Queue: Niels Moller <nisse@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#29462}

Tbr: kwiberg@webrtc.org
Bug: webrtc:10525
Change-Id: I3b61f9535aa3f1fca2ed84f068233803d4ec9fe2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/157045
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29485}
diff --git a/media/base/media_channel.h b/media/base/media_channel.h
index 8f6b04b..c3e8be5 100644
--- a/media/base/media_channel.h
+++ b/media/base/media_channel.h
@@ -393,7 +393,13 @@
       return 0;
     }
   }
-  int64_t bytes_sent = 0;
+  // TODO(nisse): Sum of below two values. Deprecated, delete as soon as
+  // downstream applications are updated.
+  int64_t bytes_sent;
+  // https://w3c.github.io/webrtc-stats/#dom-rtcsentrtpstreamstats-bytessent
+  int64_t payload_bytes_sent = 0;
+  // https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-headerbytessent
+  int64_t header_and_padding_bytes_sent = 0;
   // https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-retransmittedbytessent
   uint64_t retransmitted_bytes_sent = 0;
   int packets_sent = 0;
@@ -447,7 +453,13 @@
     }
   }
 
-  int64_t bytes_rcvd = 0;
+  // TODO(nisse): Sum of below two values. Deprecated, delete as soon as
+  // downstream applications are updated.
+  int64_t bytes_rcvd;
+  // https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-bytesreceived
+  int64_t payload_bytes_rcvd = 0;
+  // https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-headerbytesreceived
+  int64_t header_and_padding_bytes_rcvd = 0;
   int packets_rcvd = 0;
   int packets_lost = 0;
   // TODO(bugs.webrtc.org/10679): Unused, delete as soon as downstream code is