honghaiz e2af9ef638 Keep on sending stun binding requests on zero-cost networks.
This is useful to keep the NAT binding alive on backup connections.

BUG=

Review URL: https://codereview.webrtc.org/1737493004

Cr-Commit-Position: refs/heads/master@{#11862}
2016-03-03 16:27:53 +00:00
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2015-12-16 19:44:39 +00:00
2016-02-09 01:35:55 +00:00