Add a merely pass-through QuicMultipathSentPacketManager. Protected behind blocked flag FLAGS_quic_…

net/quic/quic_server_session_base_test.cc

 // 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.
 
 #include "net/quic/quic_server_session_base.h"
 
 #include <cstdint>
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 388 matching lines @@
 
 TEST_P(QuicServerSessionBaseTest, BandwidthEstimates) {
   // Test that bandwidth estimate updates are sent to the client, only when
   // bandwidth resumption is enabled, the bandwidth estimate has changed
   // sufficiently, enough time has passed,
   // and we don't have any other data to write.
 
   // Client has sent kBWRE connection option to trigger bandwidth resumption.
   // Disable this flag because if connection uses multipath sent packet manager,
   // static_cast here does not work.
-  FLAGS_quic_enable_multipath = false;
   QuicTagVector copt;
   copt.push_back(kBWRE);
   QuicConfigPeer::SetReceivedConnectionOptions(session_->config(), copt);
   session_->OnConfigNegotiated();
   EXPECT_TRUE(
       QuicServerSessionBasePeer::IsBandwidthResumptionEnabled(session_.get()));
 
   int32_t bandwidth_estimate_kbytes_per_second = 123;
   int32_t max_bandwidth_estimate_kbytes_per_second = 134;
   int32_t max_bandwidth_estimate_timestamp = 1122334455;
   const string serving_region = "not a real region";
   session_->set_serving_region(serving_region);
 
   MockQuicCryptoServerStream* crypto_stream = new MockQuicCryptoServerStream(
       &crypto_config_, &compressed_certs_cache_, session_.get());
   QuicServerSessionBasePeer::SetCryptoStream(session_.get(), crypto_stream);
 
   // Set some initial bandwidth values.
   QuicSentPacketManager* sent_packet_manager =
-      static_cast<QuicSentPacketManager*>(
-          QuicConnectionPeer::GetSentPacketManager(session_->connection()));
+      QuicConnectionPeer::GetSentPacketManager(session_->connection(),
+                                               kDefaultPathId);
   QuicSustainedBandwidthRecorder& bandwidth_recorder =
       QuicSentPacketManagerPeer::GetBandwidthRecorder(sent_packet_manager);
   // Seed an rtt measurement equal to the initial default rtt.
   RttStats* rtt_stats =
       const_cast<RttStats*>(sent_packet_manager->GetRttStats());
   rtt_stats->UpdateRtt(
       QuicTime::Delta::FromMicroseconds(rtt_stats->initial_rtt_us()),
       QuicTime::Delta::Zero(), QuicTime::Zero());
   QuicSustainedBandwidthRecorderPeer::SetBandwidthEstimate(
       &bandwidth_recorder, bandwidth_estimate_kbytes_per_second);
@@ skipping 123 matching lines @@
   EXPECT_FALSE(
       QuicServerSessionBasePeer::IsBandwidthResumptionEnabled(session_.get()));
   session_->OnConfigNegotiated();
   EXPECT_FALSE(
       QuicServerSessionBasePeer::IsBandwidthResumptionEnabled(session_.get()));
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net