Also change return type for username_fragment() to be const& and not create a copy. Bug: none Change-Id: I8591af3da54fc8a9784e13cb000c4e02c0cd2f40 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/317980 Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Cr-Commit-Position: refs/heads/main@{#40651}