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

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="chromeos">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <message name="IDS_CHROMEBOOK" desc="The localized name for Chromebook.">
     Chromebook
   </message>
   <message name="IDS_CHROMEBOX" desc="The localized name for Chromebox">
@@ skipping 3766 matching lines @@
   </message>
   <message name="IDS_STATUSBAR_NETWORK_MENU_ITEM_INDENT" desc="A menu item label with an indentation. For left-to-right languages, we use 3 spaces on the left.">
     '''   <ph name="LABEL">$1<ex>Wifi SSID</ex></ph>'''
   </message>
   <message name="IDS_STATUSBAR_NETWORK_OPEN_PROXY_SETTINGS_DIALOG" desc="The menu item in the network menu button at login screen for opening the options dialog">
     Proxy settings...
   </message>
   <message name="IDS_STATUSBAR_NETWORK_MORE" desc="Message for last link in the network menu requesting more technical and less common stuff (proxy settings, IP and hardware addresses)">
     More...
   </message>
+  <message name="IDS_STATUSBAR_NETWORK_ADD_VPN_TEMPLATE" desc="Template for constructing a menu item that will ask a given VPN provider to show its 'add network' dialog.">

[michaelpg, 2015/03/17 19:28:16]

nit: since this isn't used in the status area (on the login screen), can we give
it a name like the other internet options strings and place it near them? e.g.:
IDS_OPTIONS_SETTINGS_ADD_VPN_TEMPLATE

[bartfab (slow), 2015/03/18 21:27:14]

Done.

+    Add <ph name="PROVIDER_NAME">$1<ex>OpenVPN</ex></ph>...
+  </message>
   <message name="IDS_STATUSBAR_NETWORK_ADD_VPN" desc="In the network status menu, the text in Private networks submenu to add a private network.">
     Add private network...
   </message>
   <message name="IDS_STATUSBAR_NETWORK_VIEW_ACCOUNT" desc="In the network status menu, the text of the top-up URL link.">
     View account
   </message>
   <message name="IDS_STATUSBAR_NO_NETWORKS_MESSAGE" desc="No networks are available">
     No networks are available
   </message>
   <message name="IDS_STATUSBAR_BATTERY_CHARGING_PERCENTAGE" desc="In the power menu button, this shows what percentage of battery is left when power supply is connected.">
@@ skipping 2307 matching lines @@
   <message name="IDS_OPTIONS_CAPTIVE_PORTAL_BYPASS_PROXY_LABEL" desc="Option in chrome://settings that allows Captive Portal authorization pages to ignore proxy settings.">
     Allow captive portal sign-in page to bypass proxy servers
   </message>
   <message name="IDS_FLAGS_ENABLE_FIREWALL_HOLE_PUNCHING_NAME" desc="Name of the option to enable punching holes in the Chrome OS firewall.">
     Enable firewall hole punching.
   </message>
   <message name="IDS_FLAGS_ENABLE_FIREWALL_HOLE_PUNCHING_DESCRIPTION" desc="Description of the option to enable punching holes in the Chrome OS firewall.">
     Enable punching holes in the Chrome OS firewall for Chrome Apps that open a TCP/IP server socket or UDP socket.
   </message>
 </grit-part>