Fix race in WebRtcVideoEngine2Tests, improve coverage.

webrtc/media/engine/webrtcvideoengine2.cc

 /*
  *  Copyright (c) 2014 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 1600 matching lines @@
     if (parameters_.options.is_screencast.value_or(false) !=
             old_options.is_screencast.value_or(false) &&
         parameters_.codec_settings) {
       // If screen content settings change, we may need to recreate the codec
       // instance so that the correct type is used.
 
       bool force_encoder_allocation = true;
       SetCodec(*parameters_.codec_settings, force_encoder_allocation);
       // Mark screenshare parameter as being updated, then test for any other
       // changes that may require codec reconfiguration.
+      // TODO(sprang): Refactor code to guarantee that ReconfigureEncoder is a
+      // subset SetCodec instead, so that we don't unnecessarily reconfigure
+      // the encoder twice.
       old_options.is_screencast = options->is_screencast;
     }
     if (parameters_.options != old_options) {
       ReconfigureEncoder();
     }
   }
 
   if (source_ && stream_) {
     stream_->SetSource(
         nullptr, webrtc::VideoSendStream::DegradationPreference::kBalanced);
@@ skipping 911 matching lines @@
         rtx_mapping[video_codecs[i].codec.id] !=
             ulpfec_config.red_payload_type) {
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket