Refactor to create a new LossDetectionInterface used by the

net/quic/congestion_control/loss_detection_interface.h

Index: net/quic/congestion_control/loss_detection_interface.h
diff --git a/net/quic/congestion_control/loss_detection_interface.h b/net/quic/congestion_control/loss_detection_interface.h
new file mode 100644
index 0000000000000000000000000000000000000000..85d51e3fa1f224f2760718de7495af056e232861
--- /dev/null
+++ b/net/quic/congestion_control/loss_detection_interface.h
@@ -0,0 +1,35 @@
+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// The pure virtual class for send side loss detection algorithm.
+
+#ifndef NET_QUIC_CONGESTION_CONTROL_LOSS_DETECTION_INTERFACE_H_
+#define NET_QUIC_CONGESTION_CONTROL_LOSS_DETECTION_INTERFACE_H_
+
+#include "base/basictypes.h"
+#include "net/quic/quic_protocol.h"
+#include "net/quic/quic_time.h"
+
+namespace net {
+
+class QuicUnackedPacketMap;
+
+class NET_EXPORT_PRIVATE LossDetectionInterface {
+ public:
+  // Creates a TCP loss detector.
+  static LossDetectionInterface* Create();
+
+  virtual ~LossDetectionInterface() {}
+
+  // Called when a new ack arrives or the loss alarm fires.
+  virtual SequenceNumberSet DetectLostPackets(
+      const QuicUnackedPacketMap& unacked_packets,
+      const QuicTime& time,
+      QuicPacketSequenceNumber largest_observed,
+      QuicTime::Delta srtt) = 0;
+};
+
+}  // namespace net
+
+#endif  // NET_QUIC_CONGESTION_CONTROL_LOSS_DETECTION_INTERFACE_H_