Only cancel QUIC alarms if they have been set. Protected behind FLAG_quic_only_cancel_set_alarms

net/quic/quic_flags.cc

Index: net/quic/quic_flags.cc
diff --git a/net/quic/quic_flags.cc b/net/quic/quic_flags.cc
index b34825d0ae02316ed124c2f84280b652218122de..9fd8f3f6672e62c04f0662c80ce6a73ba6ae11f3 100644
--- a/net/quic/quic_flags.cc
+++ b/net/quic/quic_flags.cc
@@ -126,3 +126,7 @@ bool FLAGS_quic_ack_decimation2 = true;
 
 // If true, QUIC connections will defer responding to ACKs to their send alarms.
 bool FLAGS_quic_connection_defer_ack_response = true;
+
+// If true, calls to QuicAlarm::Cancel don't do anything  if the alarm is not
+// set.
+bool FLAGS_quic_only_cancel_set_alarms = true;