Quic: add histogram for number of packets that failed decryption, only if a...

Quic: add histogram for number of packets that failed decryption, only if a decryption key was present.

Bug: b/170619368
Change-Id: Ifb9e2cde75e8e6ff79ed98372b26e35f2fd65a8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2503572
Commit-Queue: Matt Mueller <mattm@chromium.org>
Reviewed-by: David Schinazi <dschinazi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821564}

net/quic/quic_chromium_client_session.cc

@@ -1944,6 +1944,9 @@ void QuicChromiumClientSession::OnConnectionClosed(
         connection()->GetStats().crypto_retransmit_count);
   }
 
+  base::UmaHistogramCounts1M(
+      "Net.QuicSession.UndecryptablePacketsReceivedWithDecrypter",
+      connection()->GetStats().num_failed_authentication_packets_received);
   base::UmaHistogramSparse("Net.QuicSession.QuicVersion",
                            connection()->transport_version());
   NotifyFactoryOfSessionGoingAway();

tools/metrics/histograms/histograms_xml/net/histograms.xml

@@ -3789,7 +3789,18 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   <owner>src/net/quic/OWNERS</owner>
   <summary>
     The number of undecryptable packets recevied by a QuicSession when the
-    sesesion is closed.
+    session is closed. Includes packets where a decryption key was not present.
+  </summary>
+</histogram>
+
+<histogram name="Net.QuicSession.UndecryptablePacketsReceivedWithDecrypter"
+    units="units" expires_after="2021-05-11">
+  <owner>mattm@chromium.org</owner>
+  <owner>src/net/quic/OWNERS</owner>
+  <summary>
+    The number of undecryptable packets recevied by a QuicSession when the
+    session is closed. Only includes packets where a decryption key was present
+    for the packet's encryption level.
   </summary>
 </histogram>