Periodically update channel parameters and send TargetBitrate message.

webrtc/video/vie_encoder.h

 /*
  *  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 217 matching lines @@
   // Used to make sure incoming time stamp is increasing for every frame.
   int64_t last_captured_timestamp_ GUARDED_BY(incoming_frame_race_checker_);
   // Delta used for translating between NTP and internal timestamps.
   const int64_t delta_ntp_internal_ms_ GUARDED_BY(incoming_frame_race_checker_);
 
   int64_t last_frame_log_ms_ GUARDED_BY(incoming_frame_race_checker_);
   int captured_frame_count_ ACCESS_ON(&encoder_queue_);
   int dropped_frame_count_ ACCESS_ON(&encoder_queue_);
 
   VideoBitrateAllocationObserver* bitrate_observer_ ACCESS_ON(&encoder_queue_);
+  rtc::Optional<int64_t> last_parameters_update_ms_ ACCESS_ON(&encoder_queue_);
 
   // All public methods are proxied to |encoder_queue_|. It must must be
   // destroyed first to make sure no tasks are run that use other members.
   rtc::TaskQueue encoder_queue_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(ViEEncoder);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_VIE_ENCODER_H_