Adds support to the PacketDroppingTestWriter for dropping the first N

net/tools/quic/test_tools/packet_dropping_test_writer.h

 // Copyright 2013 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.
 
 #ifndef NET_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_
 #define NET_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_
 
 #include <list>
 #include <string>
 
@@ skipping 51 matching lines @@
   QuicTime ReleaseOldPackets();
 
   void OnCanWrite();
 
   // The percent of time a packet is simulated as being lost.
   void set_fake_packet_loss_percentage(int32 fake_packet_loss_percentage) {
     base::AutoLock locked(config_mutex_);
     fake_packet_loss_percentage_ = fake_packet_loss_percentage;
   }
 
+  // Simulate dropping the first n packets unconditionally.
+  // Subsequent packets will be lost at fake_packet_loss_percentage_ if set.
+  void set_fake_drop_first_n_packets(int32 fake_drop_first_n_packets) {
+    base::AutoLock locked(config_mutex_);
+    fake_drop_first_n_packets_ = fake_drop_first_n_packets;
+  }
+
   // The percent of time WritePacket will block and set WriteResult's status
   // to WRITE_STATUS_BLOCKED.
   void set_fake_blocked_socket_percentage(
       int32 fake_blocked_socket_percentage) {
     DCHECK(clock_);
     base::AutoLock locked(config_mutex_);
     fake_blocked_socket_percentage_  = fake_blocked_socket_percentage;
   }
 
   // The percent of time a packet is simulated as being reordered.
@@ skipping 52 matching lines @@
   typedef std::list<DelayedWrite> DelayedPacketList;
 
   const QuicClock* clock_;
   scoped_ptr<QuicAlarm> write_unblocked_alarm_;
   scoped_ptr<QuicAlarm> delay_alarm_;
   scoped_ptr<Delegate> on_can_write_;
   net::test::SimpleRandom simple_random_;
   // Stored packets delayed by fake packet delay or bandwidth restrictions.
   DelayedPacketList delayed_packets_;
   QuicByteCount cur_buffer_size_;
+  uint64 num_calls_to_write_;
 
   base::Lock config_mutex_;
   int32 fake_packet_loss_percentage_;
+  int32 fake_drop_first_n_packets_;
   int32 fake_blocked_socket_percentage_;
   int32 fake_packet_reorder_percentage_;
   QuicTime::Delta fake_packet_delay_;
   QuicBandwidth fake_bandwidth_;
   QuicByteCount buffer_size_;
 
   DISALLOW_COPY_AND_ASSIGN(PacketDroppingTestWriter);
 };
 
 }  // namespace test
 }  // namespace tools
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_