Add a getMap function to ol.FeatureOverlay

src/ol/featureoverlay.js

@@ -112,6 +112,15 @@ ol.FeatureOverlay.prototype.getFeatures = function() {
 };
 
 
+/**
+ * @return {?ol.Map} The map with which this feature overlay is associated.
+ * @api
+ */
+ol.FeatureOverlay.prototype.getMap = function() {
+  return this.map_;
+};
+
+
 /**
  * @private
  */