Some hardware H.264 encoders does not place average QP delta in slice_qp_delta field. Adding an optional flag in EncoderInfo to notify quality scaler about this. Bug: webrtc:12942 Change-Id: I3ee29c5ae9bd7bb34d26eba7e6bede3798ca44b4 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226921 Reviewed-by: Sergey Silkin <ssilkin@webrtc.org> Reviewed-by: Erik Språng <sprang@webrtc.org> Commit-Queue: Sergey Silkin <ssilkin@webrtc.org> Cr-Commit-Position: refs/heads/master@{#34627}