Show a helpful error message if a host domain policy blocked an attempt to use

remoting/webapp/_locales/en/messages.json

Index: remoting/webapp/_locales/en/messages.json
diff --git a/remoting/webapp/_locales/en/messages.json b/remoting/webapp/_locales/en/messages.json
index 02c130f970346b662988f793b0988644ba864543..ec94dcbef6077bfb23677be15f5eaf810d6618df 100644
--- a/remoting/webapp/_locales/en/messages.json
+++ b/remoting/webapp/_locales/en/messages.json
@@ -150,6 +150,10 @@
     "message": "The access code is invalid. Please try again.",
     "description": "Error displayed if an invalid access code is entered."
   },
+  "ERROR_INVALID_HOST_DOMAIN": {
+    "message": "This computer does not let you use it as a Chromoting host.",

[Jamie, 2012/09/19 17:37:59]

For the NAT traversal warning, we specifically refer to policy settings. I think
we should do the same here. Perhaps "Policy settings do not permit sharing this
computer as a Chromoting host." Since we try to include a remedy in such
situations, I'd suggest "Contact your system administrator for assistance." as
well.

[simonmorris, 2012/09/19 18:01:02]

Done.

+    "description": "Error displayed when the computer has a policy that only users in a particular domain may use it as a Chromoting host, and a user in a different domain is trying to use it as a Chromoting host."
+  },
   "ERROR_NETWORK_FAILURE": {
     "message": "Unable to reach the host. This is probably due to the configuration of the network you are using.",
     "description": "Error displayed when the host is online, but we are unable to connect to it due to network configuration."