Reland of quest keyframes more frequently on stream start/decoding error.

webrtc/video/video_receive_stream.h

 /*
  *  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 126 matching lines @@
 
   rtc::CriticalSection ivf_writer_lock_;
   std::unique_ptr<IvfFileWriter> ivf_writer_ GUARDED_BY(ivf_writer_lock_);
 
   // Members for the new jitter buffer experiment.
   std::unique_ptr<VCMJitterEstimator> jitter_estimator_;
   std::unique_ptr<video_coding::FrameBuffer> frame_buffer_;
 
   std::unique_ptr<RtpStreamReceiverInterface> media_receiver_;
   std::unique_ptr<RtpStreamReceiverInterface> rtx_receiver_;
+
+  // Whenever we are in an undecodable state (stream has just started or due to
+  // a decoding error) we require a keyframe to restart the stream.
+  bool keyframe_required_ = true;
 };
 }  // namespace internal
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_VIDEO_RECEIVE_STREAM_H_