Log the certificate subjects from the server certificate sent via QUIC.

net/base/net_log_event_type_list.h

Index: net/base/net_log_event_type_list.h
diff --git a/net/base/net_log_event_type_list.h b/net/base/net_log_event_type_list.h
index c6ed7c5d93795c7af44cec460a9ca69ac399636b..e85ecbf33e39c6b0500d07f2118a50f99658153b 100644
--- a/net/base/net_log_event_type_list.h
+++ b/net/base/net_log_event_type_list.h
@@ -1358,6 +1358,12 @@ EVENT_TYPE(QUIC_SESSION_CLOSE_ON_ERROR)
 //   }
 EVENT_TYPE(QUIC_SESSION_PACKET_RECEIVED)
 
+// Session verified a certificate from the server.
+//   {
+//     "cert_subjects": <list of DNS names that the certs is valid for>,

[wtc, 2014/07/24 16:59:53]

1. Typo: certs => certificate

2. The certificate contains many fields. Why are you only interested in the
subject names? Would it be better to dump the entire certificate chain? You can
take a look at the NetLog::TYPE_SSL_CERTIFICATES_RECEIVED code in
net/socket/ssl_client_socket_nss.cc.

I guess you are investigating connection pooling opportunities?

[wtc, 2014/07/24 17:17:01]

Nit: you can shorten this dictionary key to "subjects" because in this context
the "cert" part is implied.

But "subjects" could be a jargon to people unfamiliar with certificates and
"cert" would help clarify it.

[Ryan Hamilton, 2014/07/24 17:24:46]

Done.
Right. For this usage, all I care about are the subjects for pooling.
TYPE_SSL_CERTIFICATES_RECEIVED dumps the whole chain, but it dumps it as a PEM
encoded blob which means it needs to be parsed externally before it can be used.
I asked agl if we had any sort of function to dump an X509Certificate similar to
openssl x509 -text, but he said we didn't. So I decided to just log the subject
instead.  Does this work for you? (I assume so since you LGTM'd) Alternatively,
I could do both?

[Ryan Hamilton, 2014/07/24 17:24:46]

Done.

[wtc, 2014/07/24 17:34:35]

This is fine by me. It's just that the reason for logging only the subjects is
not obvious. I knew it because I discussed connection pooling with you recently.
Perhaps we can add a comment to the logging function to note other fields can be
logged if needed.

[Ryan Hamilton, 2014/07/24 17:45:09]

Done.

+//   }
+EVENT_TYPE(QUIC_SESSION_CERTIFICATE_VERIFIED)

[wtc, 2014/07/24 16:59:53]

Please list this event before QUIC_SESSION_PACKET_RECEIVED. (All the events in
this section are named QUIC_SESSION_PACKET_xxx.)

[Ryan Hamilton, 2014/07/24 17:24:46]

Done.

+
 // Session sent a QUIC packet.
 //   {
 //     "encryption_level": <The EncryptionLevel of the packet>,