Add connection type to connection stats.

Add connection type to connection stats:

* Move the connection mode into the LogToServer ctor, since it never changes.
* Parse log messages, since we don't have an explicit message for connection type.
* Save the most-recent connection type for any channel, and send it with stats logs (we only know how to parse one connection type field, so this seems like the best we're going to get).

Committed: https://crrev.com/d5121f3bfd26741b31f82e585f1641ca27e1f580
Cr-Commit-Position: refs/heads/master@{#302760}

[Jamie, 2014-11-04 22:20:19]

jamiewalch@chromium.org changed reviewers:
+ rmsousa@chromium.org

[Jamie, 2014-11-04 22:20:20]

ptal

[rmsousa, 2014-11-05 03:18:43]

lgtm

[Jamie, 2014-11-05 06:15:06]

The CQ bit was checked by jamiewalch@chromium.org

[commit-bot: I haz the power, 2014-11-05 06:15:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/689473004/20001

[commit-bot: I haz the power, 2014-11-05 07:40:16]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-11-05 07:41:40]

Patchset 2 (id:??) landed as
https://crrev.com/d5121f3bfd26741b31f82e585f1641ca27e1f580
Cr-Commit-Position: refs/heads/master@{#302760}