Also take the opportunity to declare factory_ const. (Bug reference is where I noticed the possibility; it is unlikely to fix the bug.) Bug: chromium:1205343 Change-Id: I6078f170cf68d94314ee184bdfd2dc6f4ffc1e71 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/217385 Reviewed-by: Tommi <tommi@webrtc.org> Commit-Queue: Harald Alvestrand <hta@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33918}