Consistent use of ol.tilecoord.getKeyZXY()

src/ol/source/vectortile.js

@@ -5,8 +5,9 @@ goog.require('ol.TileState');
 goog.require('ol.VectorImageTile');
 goog.require('ol.VectorTile');
 goog.require('ol.size');
-goog.require('ol.tilegrid');
 goog.require('ol.source.UrlTile');
+goog.require('ol.tilecoord');
+goog.require('ol.tilegrid');
 
 
 /**
@@ -110,7 +111,7 @@ ol.source.VectorTile.prototype.clear = function() {
  * @inheritDoc
  */
 ol.source.VectorTile.prototype.getTile = function(z, x, y, pixelRatio, projection) {
-  var tileCoordKey = this.getKeyZXY(z, x, y);
+  var tileCoordKey = ol.tilecoord.getKeyZXY(z, x, y);
   if (this.tileCache.containsKey(tileCoordKey)) {
     return /** @type {!ol.Tile} */ (this.tileCache.get(tileCoordKey));
   } else {