Especially with the TaskQueuePacerSender, it is very common that a single packet is added to the queue and then immediately removed as it gets sent to the network. This CL adds a fast-path for that case, that avoid creating book- keeping in the form of stream-priorities and timestamp sets etc. Functionally, it should be a noop, but hopefully it can save a few CPU cycles. Bug: webrtc:10809 Change-Id: Idaa06b4f8d1da444fce78cc742e2ab52f9efe815 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/172090 Commit-Queue: Erik Språng <sprang@webrtc.org> Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Cr-Commit-Position: refs/heads/master@{#31001}