Replace NULL with nullptr in all C++ files.

webrtc/modules/video_coding/receiver.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 165 matching lines @@
              max_video_delay_ms_) {
     LOG(LS_WARNING) << "The video target delay has grown larger than "
                     << max_video_delay_ms_ << " ms. Resetting jitter buffer.";
     timing_error = true;
   }
 
   if (timing_error) {
     // Timing error => reset timing and flush the jitter buffer.
     jitter_buffer_.Flush();
     timing_->Reset();
-    return NULL;
+    return nullptr;
   }
 
   if (prefer_late_decoding) {
     // Decode frame as close as possible to the render timestamp.
     const int32_t available_wait_time =
         max_wait_time_ms -
         static_cast<int32_t>(clock_->TimeInMilliseconds() - start_time_ms);
     uint16_t new_max_wait_time =
         static_cast<uint16_t>(VCM_MAX(available_wait_time, 0));
     uint32_t wait_time_ms =
         timing_->MaxWaitingTime(render_time_ms, clock_->TimeInMilliseconds());
     if (new_max_wait_time < wait_time_ms) {
       // We're not allowed to wait until the frame is supposed to be rendered,
       // waiting as long as we're allowed to avoid busy looping, and then return
-      // NULL. Next call to this function might return the frame.
+      // null. Next call to this function might return the frame.
       render_wait_event_->Wait(new_max_wait_time);
-      return NULL;
+      return nullptr;
     }
     // Wait until it's time to render.
     render_wait_event_->Wait(wait_time_ms);
   }
 
   // Extract the frame from the jitter buffer and set the render time.
   VCMEncodedFrame* frame = jitter_buffer_.ExtractAndSetDecode(frame_timestamp);
-  if (frame == NULL) {
-    return NULL;
+  if (frame == nullptr) {
+    return nullptr;
   }
   frame->SetRenderTime(render_time_ms);
   TRACE_EVENT_ASYNC_STEP1("webrtc", "Video", frame->TimeStamp(), "SetRenderTS",
                           "render_time", frame->RenderTimeMs());
   if (!frame->Complete()) {
     // Update stats for incomplete frames.
     bool retransmitted = false;
     const int64_t last_packet_time_ms =
         jitter_buffer_.LastPacketTime(frame, &retransmitted);
     if (last_packet_time_ms >= 0 && !retransmitted) {
@@ skipping 63 matching lines @@
   timing_->set_min_playout_delay(desired_delay_ms);
   return 0;
 }
 
 void VCMReceiver::RegisterStatsCallback(
     VCMReceiveStatisticsCallback* callback) {
   jitter_buffer_.RegisterStatsCallback(callback);
 }
 
 }  // namespace webrtc