Mark |Clock*| as |const Clock*| (for some CongestionController and BWE related modules)

webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy.cc

 /*
  *  Copyright (c) 2015 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 15 matching lines @@
 const int RemoteEstimatorProxy::kBackWindowMs = 500;
 const int RemoteEstimatorProxy::kMinSendIntervalMs = 50;
 const int RemoteEstimatorProxy::kMaxSendIntervalMs = 250;
 const int RemoteEstimatorProxy::kDefaultSendIntervalMs = 100;
 
 // The maximum allowed value for a timestamp in milliseconds. This is lower
 // than the numerical limit since we often convert to microseconds.
 static constexpr int64_t kMaxTimeMs =
     std::numeric_limits<int64_t>::max() / 1000;
 
-RemoteEstimatorProxy::RemoteEstimatorProxy(Clock* clock,
+RemoteEstimatorProxy::RemoteEstimatorProxy(const Clock* clock,
                                            PacketRouter* packet_router)
     : clock_(clock),
       packet_router_(packet_router),
       last_process_time_ms_(-1),
       media_ssrc_(0),
       feedback_sequence_(0),
       window_start_seq_(-1),
       send_interval_ms_(kDefaultSendIntervalMs) {}
 
 RemoteEstimatorProxy::~RemoteEstimatorProxy() {}
@@ skipping 143 matching lines @@
     // Note: Don't erase items from packet_arrival_times_ after sending, in case
     // they need to be re-sent after a reordering. Removal will be handled
     // by OnPacketArrival once packets are too old.
     window_start_seq_ = it->first + 1;
   }
 
   return true;
 }
 
 }  // namespace webrtc