Remove unused ol.format.Feature.getExtensions function

src/ol/format/kml.js

@@ -99,14 +99,6 @@ ol.format.KML = function(opt_options) {
 ol.inherits(ol.format.KML, ol.format.XMLFeature);
 
 
-/**
- * @const
- * @type {Array.<string>}
- * @private
- */
-ol.format.KML.EXTENSIONS_ = ['.kml'];
-
-
 /**
  * @const
  * @type {Array.<string>}
@@ -1646,14 +1638,6 @@ ol.format.KML.STYLE_MAP_PARSERS_ = ol.xml.makeStructureNS(
     });
 
 
-/**
- * @inheritDoc
- */
-ol.format.KML.prototype.getExtensions = function() {
-  return ol.format.KML.EXTENSIONS_;
-};
-
-
 /**
  * @param {Node} node Node.
  * @param {Array.<*>} objectStack Object stack.