Rename enterprise policy proto fields from KIOSK to RETAIL.

chrome/browser/policy/proto/device_management_backend.proto

Index: chrome/browser/policy/proto/device_management_backend.proto
diff --git a/chrome/browser/policy/proto/device_management_backend.proto b/chrome/browser/policy/proto/device_management_backend.proto
index 9db8cc93e3fbd0668ad30b3750113d926d4487bf..ea0d31eca742b72fd9f09e736aee251cb86e2eae 100644
--- a/chrome/browser/policy/proto/device_management_backend.proto
+++ b/chrome/browser/policy/proto/device_management_backend.proto
@@ -64,10 +64,10 @@ message DeviceRegisterResponse {
     // controlled through the cloud policy infrastructure. Auto-enrollment is
     // supported in that mode.
     ENTERPRISE = 0;
-    // Devices in KIOSK mode also have no local owner and get their device
+    // Devices in RETAIL mode also have no local owner and get their device
     // settings from the cloud, but additionally this mode enables the demo
     // account on the device.
-    KIOSK = 1;
+    RETAIL = 1;
   }
   optional DeviceMode enrollment_type = 3 [default = ENTERPRISE];
 }