Do not call OnDecoderTiming before timing values are set.

webrtc/modules/video_coding/video_receiver.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 56 matching lines @@
     }
 
     if (_decoderTimingCallback != nullptr) {
       int decode_ms;
       int max_decode_ms;
       int current_delay_ms;
       int target_delay_ms;
       int jitter_buffer_ms;
       int min_playout_delay_ms;
       int render_delay_ms;
-      _timing->GetTimings(&decode_ms, &max_decode_ms, &current_delay_ms,
-                          &target_delay_ms, &jitter_buffer_ms,
-                          &min_playout_delay_ms, &render_delay_ms);
-      _decoderTimingCallback->OnDecoderTiming(
-          decode_ms, max_decode_ms, current_delay_ms, target_delay_ms,
-          jitter_buffer_ms, min_playout_delay_ms, render_delay_ms);
+      if (_timing->GetTimings(&decode_ms, &max_decode_ms, &current_delay_ms,
+                              &target_delay_ms, &jitter_buffer_ms,
+                              &min_playout_delay_ms, &render_delay_ms)) {
+        _decoderTimingCallback->OnDecoderTiming(
+            decode_ms, max_decode_ms, current_delay_ms, target_delay_ms,
+            jitter_buffer_ms, min_playout_delay_ms, render_delay_ms);
+      }
     }
   }
 
   // Key frame requests
   if (_keyRequestTimer.TimeUntilProcess() == 0) {
     _keyRequestTimer.Processed();
     bool request_key_frame = false;
     {
       rtc::CritScope cs(&process_crit_);
       request_key_frame = _scheduleKeyRequest && _frameTypeCallback != nullptr;
@@ skipping 421 matching lines @@
   _receiver.SetNackSettings(max_nack_list_size, max_packet_age_to_nack,
                             max_incomplete_time_ms);
 }
 
 int VideoReceiver::SetMinReceiverDelay(int desired_delay_ms) {
   return _receiver.SetMinReceiverDelay(desired_delay_ms);
 }
 
 }  // namespace vcm
 }  // namespace webrtc