Add experimental simulcast screen content mode

webrtc/media/engine/webrtcvideoengine2.h

 /*
  *  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 329 matching lines @@
     rtc::AsyncInvoker invoker_;
     rtc::Thread* worker_thread_;
     const std::vector<uint32_t> ssrcs_ ACCESS_ON(&thread_checker_);
     const std::vector<SsrcGroup> ssrc_groups_ ACCESS_ON(&thread_checker_);
     webrtc::Call* const call_;
     const bool enable_cpu_overuse_detection_;
     rtc::VideoSourceInterface<webrtc::VideoFrame>* source_
         ACCESS_ON(&thread_checker_);
     WebRtcVideoEncoderFactory* const external_encoder_factory_
         ACCESS_ON(&thread_checker_);
+    const std::unique_ptr<WebRtcVideoEncoderFactory> internal_encoder_factory_
+        ACCESS_ON(&thread_checker_);
 
     rtc::CriticalSection lock_;
     webrtc::VideoSendStream* stream_ ACCESS_ON(&thread_checker_);
     rtc::VideoSinkInterface<webrtc::VideoFrame>* encoder_sink_
         GUARDED_BY(lock_);
     // Contains settings that are the same for all streams in the MediaChannel,
     // such as codecs, header extensions, and the global bitrate limit for the
     // entire channel.
     VideoSendStreamParameters parameters_ ACCESS_ON(&thread_checker_);
     // Contains settings that are unique for each stream, such as max_bitrate.
@@ skipping 151 matching lines @@
   // send_params/recv_params, rtp_extensions, options, etc.
   VideoSendParameters send_params_;
   VideoOptions default_send_options_;
   VideoRecvParameters recv_params_;
   int64_t last_stats_log_ms_;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOENGINE2_H_