Change the pacing sender to always pacing the initial burst, even when

net/quic/quic_connection.cc

 // Copyright (c) 2012 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/quic_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 
 #include <algorithm>
@@ skipping 1157 matching lines @@
   WritePendingRetransmissions();
 
   // Sending queued packets may have caused the socket to become write blocked,
   // or the congestion manager to prohibit sending.  If we've sent everything
   // we had queued and we're still not blocked, let the visitor know it can
   // write more.
   if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
     return;
   }
 
-  {  // Limit the scope of the bundler.
-    // Set |include_ack| to false in bundler; ack inclusion happens elsewhere.
+  { // Limit the scope of the bundler. ACK inclusion happens elsewhere.
     ScopedPacketBundler bundler(this, NO_ACK);
     visitor_->OnCanWrite();
   }
 
   // After the visitor writes, it may have caused the socket to become write
   // blocked or the congestion manager to prohibit sending, so check again.
   if (visitor_->WillingAndAbleToWrite() &&
       !resume_writes_alarm_->IsSet() &&
       CanWrite(HAS_RETRANSMITTABLE_DATA)) {
     // We're not write blocked, but some stream didn't write out all of its
@@ skipping 124 matching lines @@
   QuicTime::Delta delay = sent_packet_manager_.TimeUntilSend(
       now, retransmittable);
   if (delay.IsInfinite()) {
     send_alarm_->Cancel();
     return false;
   }
 
   // If the scheduler requires a delay, then we can not send this packet now.
   if (!delay.IsZero()) {
     send_alarm_->Update(now.Add(delay), QuicTime::Delta::FromMilliseconds(1));
-    DVLOG(1) << "Delaying sending.";
+    DVLOG(1) << ENDPOINT << "Delaying sending " << delay.ToMilliseconds()
+             << "ms";
     return false;
   }
   send_alarm_->Cancel();
   return true;
 }
 
 bool QuicConnection::WritePacket(QueuedPacket* packet) {
   if (!WritePacketInner(packet)) {
     return false;
   }
@@ skipping 696 matching lines @@
   }
   for (size_t i = 0; i < retransmittable_frames->frames().size(); ++i) {
     if (retransmittable_frames->frames()[i].type == CONNECTION_CLOSE_FRAME) {
       return true;
     }
   }
   return false;
 }
 
 }  // namespace net