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 56a2704c442cae542fe42cf526b99345a443a838..cc022c4ce7c0cb704b16be4f5ccaab9dcadc3255 100644
--- a/sync/protocol/proto_value_conversions.cc
+++ b/sync/protocol/proto_value_conversions.cc
@@ -783,6 +783,15 @@ 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();
@@ -817,6 +826,7 @@ base::DictionaryValue* EntitySpecificsToValue(
             SyncedNotificationAppInfoSpecificsToValue);
   SET_FIELD(theme, ThemeSpecificsToValue);
   SET_FIELD(typed_url, TypedUrlSpecificsToValue);
+  SET_FIELD(wifi_credential, WifiCredentialSpecificsToValue);
   return value;
 }