db53f8e604
STUN candidates use STUN binding requests to keep NAT bindings open. The interval at which the STUN keepalive pings are sent is configurable now via RTCConfiguration. TBR=sakal@webrtc.org Bug: None Change-Id: I5f99ea3fe1e9042fa2bf7dcab0aace78f57739e6 Reviewed-on: https://webrtc-review.googlesource.com/54180 Commit-Queue: Qingsi Wang <qingsi@google.com> Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22109}