Replace NULL with nullptr in all C++ files.

webrtc/modules/video_coding/codecs/vp8/realtime_temporal_layers.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.
 */
 
 #include <stdlib.h>
@@ skipping 201 matching lines @@
 
     return true;
   }
 
   int EncodeFlags(uint32_t timestamp) override {
     frame_counter_++;
     return CurrentEncodeFlags();
   }
 
   int CurrentEncodeFlags() const {
-    assert(encode_flags_length_ > 0 && encode_flags_ != NULL);
+    assert(encode_flags_length_ > 0 && encode_flags_ != nullptr);
     int index = frame_counter_ % encode_flags_length_;
     assert(index >= 0 && index < encode_flags_length_);
     return encode_flags_[index];
   }
 
   int CurrentLayerId() const override {
-    assert(layer_ids_length_ > 0 && layer_ids_ != NULL);
+    assert(layer_ids_length_ > 0 && layer_ids_ != nullptr);
     int index = frame_counter_ % layer_ids_length_;
     assert(index >= 0 && index < layer_ids_length_);
     return layer_ids_[index];
   }
 
   void PopulateCodecSpecific(bool base_layer_sync,
                              CodecSpecificInfoVP8* vp8_info,
                              uint32_t timestamp) override {
     assert(temporal_layers_ > 0);
 
@@ skipping 62 matching lines @@
     int simulcast_id,
     int max_temporal_layers,
     uint8_t initial_tl0_pic_idx) const {
   TemporalLayers* tl =
       new RealTimeTemporalLayers(max_temporal_layers, initial_tl0_pic_idx);
   if (listener_)
     listener_->OnTemporalLayersCreated(simulcast_id, tl);
   return tl;
 }
 }  // namespace webrtc