Replace NULL with nullptr in all C++ files.

webrtc/modules/remote_bitrate_estimator/test/bwe_test_baselinefile.cc

 /*
  *  Copyright (c) 2013 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 55 matching lines @@
 
   virtual void Estimate(int64_t time_ms, uint32_t estimate_bps) {
     if (reader_.get()) {
       uint32_t read_ms = 0;
       uint32_t read_bps = 0;
       if (reader_->Read(&read_ms) && read_ms == time_ms &&
           reader_->Read(&read_bps) && read_bps == estimate_bps) {
       } else {
         printf("ERROR: Baseline differs starting at: %d ms (%d vs %d)!\n",
             static_cast<uint32_t>(time_ms), estimate_bps, read_bps);
-        reader_.reset(NULL);
+        reader_.reset(nullptr);
       }
     }
   }
 
   virtual bool VerifyOrWrite() {
     if (reader_.get()) {
       if (reader_->IsAtEnd()) {
         return true;
       } else {
         printf("ERROR: Baseline file contains more data!\n");
@@ skipping 72 matching lines @@
   result.reset(new BaseLineFileVerify(filepath, !write_output_file));
   if (write_output_file) {
     // Takes ownership of the |verifier| instance.
     result.reset(new BaseLineFileUpdate(filepath, result.release()));
   }
   return result.release();
 }
 }  // namespace bwe
 }  // namespace testing
 }  // namespace webrtc