Add ONC 'Source' configuration property

chromeos/network/onc/onc_utils.cc

Index: chromeos/network/onc/onc_utils.cc
diff --git a/chromeos/network/onc/onc_utils.cc b/chromeos/network/onc/onc_utils.cc
index 73b5deb9ac6d10354663e73cb6c7859243843b39..9eb4e500f5f1b68a3043c12844c07b43c1f5121c 100644
--- a/chromeos/network/onc/onc_utils.cc
+++ b/chromeos/network/onc/onc_utils.cc
@@ -160,12 +160,14 @@ scoped_ptr<base::DictionaryValue> Decrypt(const std::string& passphrase,
 
 std::string GetSourceAsString(ONCSource source) {
   switch (source) {
+    case ONC_SOURCE_UNKNOWN:
+      return "unknown";
+    case ONC_SOURCE_NONE:
+      return "none";
     case ONC_SOURCE_DEVICE_POLICY:
       return "device policy";
     case ONC_SOURCE_USER_POLICY:
       return "user policy";
-    case ONC_SOURCE_NONE:
-      return "none";
     case ONC_SOURCE_USER_IMPORT:
       return "user import";
   }