Add a new QUIC platform API for text utilities.

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"
 #include "net/quic/platform/api/quic_str_cat.h"
 
 using std::string;
 
 namespace net {
 
 QuicMultipathSentPacketManager::QuicMultipathSentPacketManager(
     QuicSentPacketManagerInterface* manager,
     QuicConnectionCloseDelegateInterface* delegate)
@@ skipping 300 matching lines @@
   string debug_state_by_path;
   for (size_t i = 0; i < path_managers_info_.size(); ++i) {
     if (path_managers_info_[i].manager == nullptr ||
         path_managers_info_[i].state != ACTIVE) {
       continue;
     }
     const string& debug_state = path_managers_info_[i].manager->GetDebugState();
     if (debug_state.empty()) {
       continue;
     }
-    debug_state_by_path =
-        debug_state_by_path + "[" + base::IntToString(i) + "]:" + debug_state;
+    debug_state_by_path = QuicStrCat(
+        debug_state_by_path, "[", i, "]:", debug_state);
   }
   return debug_state_by_path;
 }
 
 void QuicMultipathSentPacketManager::CancelRetransmissionsForStream(
     QuicStreamId stream_id) {
   for (PathSentPacketManagerInfo path_manager_info : path_managers_info_) {
     if (path_manager_info.manager != nullptr) {
       path_manager_info.manager->CancelRetransmissionsForStream(stream_id);
     }
@@ skipping 185 matching lines @@
     const {
   QuicSentPacketManagerInterface* path_manager =
       MaybeGetSentPacketManagerForActivePath(kDefaultPathId);
   if (path_manager == nullptr) {
     return nullptr;
   }
   return path_manager->GetSendAlgorithm();
 }
 
 }  // namespace net