Added cluster id to PacedSender::Callback::TimeToSendPacket.

webrtc/modules/pacing/bitrate_prober.h

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 53 matching lines @@
     int id = -1;
   };
 
   ProbingState probing_state_;
   // Probe bitrate per packet. These are used to compute the delta relative to
   // the previous probe packet based on the size and time when that packet was
   // sent.
   std::queue<ProbeCluster> clusters_;
   size_t packet_size_last_send_;
   int64_t time_last_send_ms_;
-  int cluster_id_;
+  int next_cluster_id_;
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_PACING_BITRATE_PROBER_H_