Land Recent QUIC Changes.

net/quic/quic_alarm.cc

Index: net/quic/quic_alarm.cc
diff --git a/net/quic/quic_alarm.cc b/net/quic/quic_alarm.cc
index e1d4a16ae9c1d2a99dc929bac84884777a767a85..b5aca8caa175aae288f0d6f7c23f39b61bfed29a 100644
--- a/net/quic/quic_alarm.cc
+++ b/net/quic/quic_alarm.cc
@@ -27,6 +27,19 @@ void QuicAlarm::Cancel() {
   CancelImpl();
 }
 
+void QuicAlarm::Update(QuicTime deadline, QuicTime::Delta granularity) {
+  if (!deadline.IsInitialized()) {
+    Cancel();
+    return;
+  }
+  if (std::abs(deadline.Subtract(deadline_).ToMicroseconds()) <
+          granularity.ToMicroseconds()) {
+    return;
+  }
+  Cancel();
+  Set(deadline);
+}
+
 bool QuicAlarm::IsSet() const {
   return deadline_.IsInitialized();
 }