Introduce dchecked_cast, and start using it

webrtc/modules/congestion_controller/probe_controller.cc

 /*
  *  Copyright (c) 2016 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 211 matching lines @@
     int64_t now_ms,
     std::initializer_list<int64_t> bitrates_to_probe,
     bool probe_further) {
   for (int64_t bitrate : bitrates_to_probe) {
     int64_t max_probe_bitrate_bps =
         max_bitrate_bps_ > 0 ? max_bitrate_bps_ : kDefaultMaxProbingBitrateBps;
     if (bitrate > max_probe_bitrate_bps) {
       bitrate = max_probe_bitrate_bps;
       probe_further = false;
     }
-    pacer_->CreateProbeCluster(rtc::checked_cast<int>(bitrate));
+    pacer_->CreateProbeCluster(rtc::dchecked_cast<int>(bitrate));
   }
   time_last_probing_initiated_ms_ = now_ms;
   if (probe_further) {
     state_ = State::kWaitingForProbingResult;
     min_bitrate_to_probe_further_bps_ =
         (*(bitrates_to_probe.end() - 1)) * kRepeatedProbeMinPercentage / 100;
   } else {
     state_ = State::kProbingComplete;
     min_bitrate_to_probe_further_bps_ = kExponentialProbingDisabled;
   }
 }
 
 }  // namespace webrtc