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

webrtc/modules/bitrate_controller/bitrate_controller_impl.cc

 /*
  *  Copyright (c) 2012 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 71 matching lines @@
     owner_->OnReceivedRtcpReceiverReport(fraction_lost_aggregate, rtt,
                                          total_number_of_packets, now_ms);
   }
 
  private:
   std::map<uint32_t, uint32_t> ssrc_to_last_received_extended_high_seq_num_;
   BitrateControllerImpl* owner_;
 };
 
 BitrateController* BitrateController::CreateBitrateController(
-    Clock* clock,
+    const Clock* clock,
     BitrateObserver* observer,
     RtcEventLog* event_log) {
   return new BitrateControllerImpl(clock, observer, event_log);
 }
 
 BitrateController* BitrateController::CreateBitrateController(
-    Clock* clock,
+    const Clock* clock,
     RtcEventLog* event_log) {
   return CreateBitrateController(clock, nullptr, event_log);
 }
 
-BitrateControllerImpl::BitrateControllerImpl(Clock* clock,
+BitrateControllerImpl::BitrateControllerImpl(const Clock* clock,
                                              BitrateObserver* observer,
                                              RtcEventLog* event_log)
     : clock_(clock),
       observer_(observer),
       last_bitrate_update_ms_(clock_->TimeInMilliseconds()),
       event_log_(event_log),
       bandwidth_estimation_(event_log),
       reserved_bitrate_bps_(0),
       last_bitrate_bps_(0),
       last_fraction_loss_(0),
@@ skipping 169 matching lines @@
   bandwidth_estimation_.CurrentEstimate(&bitrate, &fraction_loss, &rtt);
   if (bitrate > 0) {
     bitrate = bitrate - std::min<int>(bitrate, reserved_bitrate_bps_);
     bitrate = std::max(bitrate, bandwidth_estimation_.GetMinBitrate());
     *bandwidth = bitrate;
     return true;
   }
   return false;
 }
 }  // namespace webrtc