honghaiz 97aacee11d Filter out the network in networkmonitor if the linkProperties is null.
It may be null if the network is unknown.
Also revised the logging to replace network id with network.toString(). They are pretty much the same for logging but network.toString does not need to parse the int value.

BUG=

Review URL: https://codereview.webrtc.org/1774343002

Cr-Commit-Position: refs/heads/master@{#11925}
2016-03-09 04:50:03 +00:00
..