Update vpnProvider documentation

Update vpnProvider documentation

Fix a broken HTML tag, and add a note about future extensions to the API.

BUG=514343
Committed: https://crrev.com/b46adaf6e10577d719125aa9308ff8ce6d781607
Cr-Commit-Position: refs/heads/master@{#383782}

[Kevin Cernekee, 2016-03-29 04:28:07]

cernekee@chromium.org changed reviewers:
+ asargent@chromium.org, bartfab@chromium.org

[asargent_no_longer_on_chrome, 2016-03-29 17:19:25]

lgtm

[Kevin Cernekee, 2016-03-29 18:05:26]

The CQ bit was checked by cernekee@chromium.org

[commit-bot: I haz the power, 2016-03-29 18:05:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1838073003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1838073003/1

[commit-bot: I haz the power, 2016-03-29 18:52:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-29 18:53:26]

Description was changed from

==========
Update vpnProvider documentation

Fix a broken HTML tag, and add a note about future extensions to the API.

BUG=514343
==========

to

==========
Update vpnProvider documentation

Fix a broken HTML tag, and add a note about future extensions to the API.

BUG=514343

Committed: https://crrev.com/b46adaf6e10577d719125aa9308ff8ce6d781607
Cr-Commit-Position: refs/heads/master@{#383782}
==========

[commit-bot: I haz the power, 2016-03-29 18:53:27]

Patchset 1 (id:??) landed as
https://crrev.com/b46adaf6e10577d719125aa9308ff8ce6d781607
Cr-Commit-Position: refs/heads/master@{#383782}