sync: add WIFI_CREDENTIALS protobuf, ModelType, and preference

sync/protocol/proto_value_conversions.cc

Index: sync/protocol/proto_value_conversions.cc
diff --git a/sync/protocol/proto_value_conversions.cc b/sync/protocol/proto_value_conversions.cc
index e25bd0140acee2db3ea1ab7ac56602a8a8a2798a..612e234dd526b3732c27e3c32da6dff9d844fe48 100644
--- a/sync/protocol/proto_value_conversions.cc
+++ b/sync/protocol/proto_value_conversions.cc
@@ -858,6 +858,15 @@ base::DictionaryValue* TypedUrlSpecificsToValue(
   return value;
 }
 
+base::DictionaryValue* WifiCredentialSpecificsToValue(
+    const sync_pb::WifiCredentialSpecifics& proto) {
+  base::DictionaryValue* value = new base::DictionaryValue();
+  SET_BYTES(ssid);
+  SET_ENUM(security_class, GetWifiCredentialSecurityClassString);
+  SET_BYTES(passphrase);
+  return value;
+}
+
 base::DictionaryValue* EntitySpecificsToValue(
     const sync_pb::EntitySpecifics& specifics) {
   base::DictionaryValue* value = new base::DictionaryValue();
@@ -893,6 +902,7 @@ base::DictionaryValue* EntitySpecificsToValue(
             SyncedNotificationAppInfoSpecificsToValue);
   SET_FIELD(theme, ThemeSpecificsToValue);
   SET_FIELD(typed_url, TypedUrlSpecificsToValue);
+  SET_FIELD(wifi_credential, WifiCredentialSpecificsToValue);
   return value;
 }