Remove code for ApplicationMaxConsecutiveBytesDiscard stat

The histogram has expired long ago (July 2019).

Bug: chromium:975747
Change-Id: I5e4e8eb03ea9df2fc96f84e0e6468b4a5d4ed8d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2187772Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Commit-Queue: Harald Alvestrand <hta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#766394}

third_party/blink/renderer/platform/p2p/ipc_socket_factory.cc

@@ -251,8 +251,6 @@ IpcPacketSocket::~IpcPacketSocket() {
     Close();
   }
 
-  UMA_HISTOGRAM_CUSTOM_COUNTS("WebRTC.ApplicationMaxConsecutiveBytesDiscard.v2",
-                              max_discard_bytes_sequence_, 1, 1000000, 200);
   if (total_packets_ > 0) {
     UMA_HISTOGRAM_PERCENTAGE("WebRTC.ApplicationPercentPacketsDiscarded",
                              (packets_discarded_ * 100) / total_packets_);