Add missing WMSGetFeatureInfo exports

src/ol/source/wmssource.js

@@ -6,6 +6,13 @@ goog.require('goog.object');
 goog.require('goog.uri.utils');
 
 
+/**
+ * @typedef {{method: (ol.source.WMSGetFeatureInfoMethod|undefined),
+ *            params: (Object.<string,string>|undefined)}}
+ */
+ol.source.WMSGetFeatureInfoOptions;
+
+
 /**
  * Method to use to get WMS feature info.
  * @enum {string}