Prerender labels and cache them as images

src/ol/tilecache.js

@@ -12,25 +12,12 @@ goog.require('ol.structs.LRUCache');
  */
 ol.TileCache = function(opt_highWaterMark) {
 
-  ol.structs.LRUCache.call(this);
-
-  /**
-   * @type {number}
-   */
-  this.highWaterMark = opt_highWaterMark !== undefined ? opt_highWaterMark : 2048;
+  ol.structs.LRUCache.call(this, opt_highWaterMark);
 
 };
 ol.inherits(ol.TileCache, ol.structs.LRUCache);
 
 
-/**
- * @return {boolean} Can expire cache.
- */
-ol.TileCache.prototype.canExpireCache = function() {
-  return this.getCount() > this.highWaterMark;
-};
-
-
 /**
  * @param {Object.<string, ol.TileRange>} usedTiles Used tiles.
  */