Implement an early retransmit timer in QUIC's TcpLossAlgorithm to

net/quic/congestion_control/tcp_loss_algorithm.h

Index: net/quic/congestion_control/tcp_loss_algorithm.h
diff --git a/net/quic/congestion_control/tcp_loss_algorithm.h b/net/quic/congestion_control/tcp_loss_algorithm.h
index a542daa4d96792d36405646023b416620e7db221..67bb2b7604d90ca7f59997b861167036f3ea5b4e 100644
--- a/net/quic/congestion_control/tcp_loss_algorithm.h
+++ b/net/quic/congestion_control/tcp_loss_algorithm.h
@@ -31,8 +31,11 @@ class NET_EXPORT_PRIVATE TCPLossAlgorithm : public LossDetectionInterface {
       QuicTime::Delta srtt,
       QuicTime::Delta latest_rtt) OVERRIDE;
 
-  // Return QuicTime::Zero.
+  // Returns a non-zero value when the early retransmit timer is active.
   virtual QuicTime GetLossTimeout() const OVERRIDE;
+
+ private:
+  QuicTime loss_detection_timeout_;
 };
 
 }  // namespace net