Filter out network-change event with a null interface name.

Filter out network-change event with a null interface name.
This fixes an Android native crash.
This has happened occasionally.

BUG=
R=glaznev@webrtc.org

Committed: https://crrev.com/13e433902da05539319f4609d02ac44631e0796c
Cr-Commit-Position: refs/heads/master@{#11919}

[honghaiz3, 2016-03-08 17:07:14]

honghaiz@webrtc.org changed reviewers:
+ glaznev@webrtc.org

[honghaiz3, 2016-03-08 17:07:14]

This will fix a recent ApprtcDemo crash where the OS reported an Address change
with a null interface name. 
I will add tests in a separate CL, which will require some convoluted mocking. 
Thanks.

[honghaiz3, 2016-03-08 17:13:59]

Patchset #1 (id:1) has been deleted

[AlexG, 2016-03-08 19:34:02]

lgtm

[honghaiz3, 2016-03-08 19:42:40]

The CQ bit was checked by honghaiz@webrtc.org

[commit-bot: I haz the power, 2016-03-08 19:42:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1771383002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1771383002/20001

[commit-bot: I haz the power, 2016-03-08 21:10:25]

Description was changed from

==========
Filter out network-change event with a null interface name.
This fixes an Android native crash.
This has happened occasionally.

BUG=
==========

to

==========
Filter out network-change event with a null interface name.
This fixes an Android native crash.
This has happened occasionally.

BUG=
R=glaznev@webrtc.org

Committed: https://crrev.com/13e433902da05539319f4609d02ac44631e0796c
Cr-Commit-Position: refs/heads/master@{#11919}
==========

[honghaiz3, 2016-03-08 21:10:26]

Description was changed from

==========
Filter out network-change event with a null interface name.
This fixes an Android native crash.
This has happened occasionally.

BUG=
R=glaznev@webrtc.org

Committed: https://crrev.com/13e433902da05539319f4609d02ac44631e0796c
Cr-Commit-Position: refs/heads/master@{#11919}
==========

to

==========
Filter out network-change event with a null interface name.
This fixes an Android native crash.
This has happened occasionally.

BUG=
R=glaznev@webrtc.org

Committed:
https://chromium.googlesource.com/external/webrtc/+/13e433902da05539319f4609d...
==========

[commit-bot: I haz the power, 2016-03-08 21:10:26]

Patchset 1 (id:??) landed as
https://crrev.com/13e433902da05539319f4609d02ac44631e0796c
Cr-Commit-Position: refs/heads/master@{#11919}

[honghaiz3, 2016-03-08 21:10:27]

Committed patchset #1 (id:20001) manually as
13e433902da05539319f4609d02ac44631e0796c (presubmit successful).