Put Kiosk App parameters into device settings.

chrome/browser/chromeos/policy/proto/chrome_device_policy.proto

Index: chrome/browser/chromeos/policy/proto/chrome_device_policy.proto
diff --git a/chrome/browser/chromeos/policy/proto/chrome_device_policy.proto b/chrome/browser/chromeos/policy/proto/chrome_device_policy.proto
index 862f518b60ac5492e7640aeb1827f565c99471a7..a65f993e11abc6d9dccb15c7addad24a3eee81a5 100644
--- a/chrome/browser/chromeos/policy/proto/chrome_device_policy.proto
+++ b/chrome/browser/chromeos/policy/proto/chrome_device_policy.proto
@@ -229,9 +229,20 @@ message DeviceLocalAccountInfoProto {
   // Identifier for the device-local account. Account identifiers loosely follow
   // the conventions for email addresses as specified by RFC 5322, e.g. local
   // (user name) and domain parts, separated by the '@' character.
-  // Policy-configured device-local accounts are on the same domain that the
-  // device is enrolled to. In contrast to RFC 5322 (which is more restrictive),
-  // the local part may contain any characters other than '@'.
+  //
+  // Device-local accounts are within subdomains of localhost:
+  //  * The public-accounts.localhost domain indicates a Public Account. This is
+  //    a special account type providing login-less, ephemeral,
+  //    policy-preconfigured browsing sessions.
+  //  * Legacy policy-configured Public Accounts are on the same domain that the
+  //    device is enrolled to. In contrast to RFC 5322 (which is more
+  //    restrictive), the local part may contain any characters other than '@'.
+  //    Legacy account identifiers of the form user@domain are treated as if
+  //    they were specified as user@domain.public-accounts.localhost.
+  //  * <appid>@kiosk-apps.localhost is used for configuring Kiosk Apps, which
+  //    may be started from the login screen and run the specified application
+  //    in full-screen mode. <appid> is the standard 32-character Chrome App
+  //    identifier.
   optional string id = 1;

[kenlin, 2013/04/23 18:09:42]

Did I understand correctly that by using <appid>@kiosk-apps.localhost
convention, Chrome OS device will understand appId is the app to download and
run?  Does it assume CWS will host the app?  Can we any other websites hosting
the app?

[Mattias Nissler (ping if slow), 2013/04/23 18:28:10]

Good point. Maybe it's not such a bright idea to use the same field for kiosk
apps and device-local accounts after all? I'd like to reuse the auto-login part
though to avoid ambiguity. I'll think more about this and update the CL tomorrow
with a proposal.

 }
 
@@ -248,6 +259,12 @@ message DeviceLocalAccountsProto {
   // The amount of time, in milliseconds, that should elapse at the signin
   // screen without user interaction before automatically logging in.
   optional int64 auto_login_delay = 3;
+
+  // Whether the keyboard shortcut to prevent zero-delay auto-login should be
+  // enabled or not. If this keyboard shortcut is engaged, the auto-login will
+  // be delayed by 3 minutes so administrators can log in or make configuration
+  // changes.
+  optional bool enable_auto_login_bailout = 4 [default = true];
 }
 
 message AllowRedeemChromeOsRegistrationOffersProto {