A number of utility functions to be shared between frame buffer 2 and the new frame scheduling implementation based on frame buffer 3. Change-Id: Icc932c6c76fddeeedc8aa64ec27c7e0c955abfd0 Bug: webrtc:13343 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/241604 Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Reviewed-by: Philip Eliasson <philipel@webrtc.org> Commit-Queue: Evan Shrubsole <eshr@webrtc.org> Cr-Commit-Position: refs/heads/main@{#35743}