This removes speculative refresh of reference buffers on key frame in WebRTC VP9 encoder wrapper and updates relevant unit tests. Bug: webrtc:10437 Change-Id: Icd178f9dbbd19af87e3ec782f9a6cecc98d47139 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/128611 Commit-Queue: Sergey Silkin <ssilkin@webrtc.org> Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Cr-Commit-Position: refs/heads/master@{#27229}