Allow congestion controller state to be accessed by the debug visitors.

net/quic/core/quic_multipath_sent_packet_manager.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/core/quic_multipath_sent_packet_manager.h"
 
 #include <cstdint>
 
 #include "base/strings/string_number_conversions.h"
 #include "net/quic/core/quic_bug_tracker.h"
@@ skipping 503 matching lines @@
 void QuicMultipathSentPacketManager::OnApplicationLimited() {
   for (PathSentPacketManagerInfo& path_manager_info : path_managers_info_) {
     if (path_manager_info.manager == nullptr ||
         path_manager_info.state != ACTIVE) {
       continue;
     }
     path_manager_info.manager->OnApplicationLimited();
   }
 }
 
+const SendAlgorithmInterface* QuicMultipathSentPacketManager::GetSendAlgorithm()
+    const {
+  QuicSentPacketManagerInterface* path_manager =
+      MaybeGetSentPacketManagerForActivePath(kDefaultPathId);
+  if (path_manager == nullptr) {
+    return nullptr;
+  }
+  return path_manager->GetSendAlgorithm();
+}
+
 }  // namespace net