According to our previous data from trace_event with using direct memcpy and libyuv::CopyPlane on chromebook atlas, the average cpu duration is 0.624ms and 0.541ms, so using libyuv::CopyPlane is 13.3% faster than direct memcpy. Bug: webrtc:12496 Change-Id: I1c41424b402a7eec34052c67933f2e88eaf0a8f4 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/196485 Reviewed-by: Tommi <tommi@webrtc.org> Commit-Queue: Tommi <tommi@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33344}