Fix a newly introduced bug in QUIC's PacingSender where burst_tokens_

net/quic/congestion_control/pacing_sender_test.cc

 // Copyright (c) 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.
 
 #include "net/quic/congestion_control/pacing_sender.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/test_tools/mock_clock.h"
@@ skipping 219 matching lines @@
   CheckPacketIsSentImmediately();
   CheckPacketIsSentImmediately();
   CheckPacketIsSentImmediately();
 
   // The first packet was a "make up", then we sent two packets "into the
   // future", so the delay should be 2.
   CheckPacketIsDelayed(QuicTime::Delta::FromMilliseconds(2));
   clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(5));
   CheckPacketIsSentImmediately();
 
-  // Now reduce bytes in flight back to 0 by and ensure another burst of 10 can
-  // be sent.
-  EXPECT_CALL(*mock_sender_, OnCongestionEvent(true, 0, _, _));
-  pacing_sender_->OnCongestionEvent(true, 0, empty_map, empty_map);
+  // Next time TimeUntilSend is called with no bytes in flight, the tokens
+  // should be refilled and there should be no delay.
+  EXPECT_CALL(*mock_sender_,
+              TimeUntilSend(clock_.Now(),
+                            0,
+                            HAS_RETRANSMITTABLE_DATA)).
+      WillOnce(Return(zero_time_));
+  EXPECT_EQ(zero_time_,
+            pacing_sender_->TimeUntilSend(clock_.Now(),
+                                          0,
+                                          HAS_RETRANSMITTABLE_DATA));
   for (int i = 0 ; i < 10; ++i) {
     CheckPacketIsSentImmediately();
   }
 
   CheckPacketIsSentImmediately();
   CheckPacketIsSentImmediately();
   CheckPacketIsSentImmediately();
 
   CheckPacketIsDelayed(QuicTime::Delta::FromMilliseconds(2));
 }
 
 }  // namespace test
 }  // namespace net