Add three new histogram to tracking QUIC packet reordering:

net/quic/quic_client_session.cc

Index: net/quic/quic_client_session.cc
diff --git a/net/quic/quic_client_session.cc b/net/quic/quic_client_session.cc
index b9a3d3dea1af5ef27bd883e529e8ba60393da16b..0cbc92cc82cbabf8b26637e9a1f70a2a80f22317 100644
--- a/net/quic/quic_client_session.cc
+++ b/net/quic/quic_client_session.cc
@@ -243,6 +243,17 @@ QuicClientSession::~QuicClientSession() {
                                   round_trip_handshakes, 0, 3, 4);
     }
   }
+  const QuicConnectionStats stats = connection()->GetStats();
+  uint64 reordering =
+      GG_UINT64_C(100) * stats.max_time_reordering_us / stats.min_rtt_us;
+    UMA_HISTOGRAM_CUSTOM_COUNTS("Net.QuicSession.MaxReorderingTime",
+                                reordering, 0, 100, 50);
+  if (stats.min_rtt_us > 100) {
+    UMA_HISTOGRAM_CUSTOM_COUNTS("Net.QuicSession.MaxReorderingTimeLongRtt",
+                                reordering, 0, 100, 50);
+  }
+  UMA_HISTOGRAM_COUNTS("Net.QuicSession.MaxReordering",
+                       stats.max_sequence_reordering);
 }
 
 void QuicClientSession::OnStreamFrames(