Remove FlushRequestsForTest Rename test constant Remove HasPendingRequestForTest Bug: webrtc:13892 Change-Id: I78e13d229742c40743465b5fb57480c24d7417c1 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/258722 Auto-Submit: Tomas Gunnarsson <tommi@webrtc.org> Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/main@{#37466}