Replace NULL with nullptr in all C++ files.

webrtc/modules/remote_bitrate_estimator/test/bwe.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 81 matching lines @@
     case kSendSideEstimator:
       return new SendSideBweSender(kbps, observer, clock);
     case kNadaEstimator:
       return new NadaBweSender(kbps, observer, clock);
     case kTcpEstimator:
       FALLTHROUGH();
     case kNullEstimator:
       return new NullBweSender();
   }
   assert(false);
-  return NULL;
+  return nullptr;
 }
 
 BweReceiver* CreateBweReceiver(BandwidthEstimatorType type,
                                int flow_id,
                                bool plot) {
   switch (type) {
     case kRembEstimator:
       return new RembReceiver(flow_id, plot);
     case kSendSideEstimator:
       return new SendSideBweReceiver(flow_id);
     case kNadaEstimator:
       return new NadaBweReceiver(flow_id);
     case kTcpEstimator:
       return new TcpBweReceiver(flow_id);
     case kNullEstimator:
       return new BweReceiver(flow_id);
   }
   assert(false);
-  return NULL;
+  return nullptr;
 }
 
 // Take into account all LinkedSet content.
 void BweReceiver::UpdateLoss() {
   loss_account_.Add(LinkedSetPacketLossRatio());
 }
 
 // Preserve 10% latest packets and update packet loss based on the oldest
 // 90%, that will be removed.
 void BweReceiver::RelieveSetAndUpdateLoss() {
@@ skipping 139 matching lines @@
 
 float LossAccount::LossRatio() {
   if (num_total == 0)
     return 0.0f;
   return static_cast<float>(num_lost) / num_total;
 }
 
 }  // namespace bwe
 }  // namespace testing
 }  // namespace webrtc