Revert of Allow users to add third-party VPNs from the settings page

Revert of Allow users to add third-party VPNs from the settings page (patchset #5 id:80001 of https://codereview.chromium.org/1017443002/)

Reason for revert:
Invalid JS caught by Closure bots:
http://build.chromium.org/p/chromium.fyi/builders/Closure%20Compilation%20Linux/builds/18417/steps/compile/logs/stdio

Original issue's description:
> Allow users to add third-party VPNs from the settings page
>
> This CL adds "Add $provider..." entries to the "Private network" and
> "Add connection" drop-down menus on the Chrome OS settings page. The
> contents of these menus updates dynamically as VPN providers are
> added/removed.
>
> BUG=460428
> TEST=Manual
>
> Committed: https://crrev.com/4f6e1a2ded3a56e7c2d1360b94990b025a309ecb
> Cr-Commit-Position: refs/heads/master@{#321395}

TBR=michaelpg@chromium.org,stevenjb@chromium.org,isherman@chromium.org,bartfab@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=460428
Committed: https://crrev.com/8cf549e719623e056e46715bdf2b488ea1bad09f
Cr-Commit-Position: refs/heads/master@{#321402}

[Dan Beam, 2015-03-19 19:03:20]

Created Revert of Allow users to add third-party VPNs from the settings page

[commit-bot: I haz the power, 2015-03-19 19:03:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1026463003/1

[commit-bot: I haz the power, 2015-03-19 19:04:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-19 19:06:03]

Patchset 1 (id:??) landed as
https://crrev.com/8cf549e719623e056e46715bdf2b488ea1bad09f
Cr-Commit-Position: refs/heads/master@{#321402}