Test divisor for zero before generating statistic

r=rch
BUG=377194
NOTRY=true

Review URL: https://codereview.chromium.org/299423002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272791 0039d316-1c4b-4281-b951-d872f2087c98

net/quic/quic_client_session.cc

@@ -244,9 +244,9 @@ QuicClientSession::~QuicClientSession() {
     }
   }
   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",
+  uint64 reordering = (stats.min_rtt_us == 0) ? GG_UINT64_C(100)
+      : 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",