Add histogram to log whether a QuicGoAwayFrame is received for connection migration.

net/quic/quic_connection_logger.cc

Index: net/quic/quic_connection_logger.cc
diff --git a/net/quic/quic_connection_logger.cc b/net/quic/quic_connection_logger.cc
index fe529d882b21d32425f8c6cd7d0e327d0fb9b9dd..5180e9b0c173f2d9737362cab129b0ecb89d0c8f 100644
--- a/net/quic/quic_connection_logger.cc
+++ b/net/quic/quic_connection_logger.cc
@@ -613,6 +613,9 @@ void QuicConnectionLogger::OnBlockedFrame(const QuicBlockedFrame& frame) {
 }
 
 void QuicConnectionLogger::OnGoAwayFrame(const QuicGoAwayFrame& frame) {
+  UMA_HISTOGRAM_BOOLEAN("Net.QuicSession.GoAwayReceivedForConnectionMigration",
+                        frame.reason_phrase == "peer connection migration");

[Alexei Svitkine (slow), 2016/03/09 18:58:20]

Can "peer connection migration" be a constant defined somewhere and used from
both the code that emits it and here? This way, if the string changes, this
doesn't break.

[Ryan Hamilton, 2016/03/09 19:06:14]

Good idea.

[Zhongyi Shi, 2016/03/10 00:42:22]

Done.

+
   net_log_.AddEvent(NetLog::TYPE_QUIC_SESSION_GOAWAY_FRAME_RECEIVED,
                     base::Bind(&NetLogQuicGoAwayFrameCallback, &frame));
 }