Merge pull request #2423 from fredj/dispose

Dispose the tiles removed from the cache

src/ol/map.js

@@ -330,6 +330,7 @@ ol.Map = function(options) {
    * @private
    */
   this.viewportSizeMonitor_ = new goog.dom.ViewportSizeMonitor();
+  this.registerDisposable(this.viewportSizeMonitor_);
 
   goog.events.listen(this.viewportSizeMonitor_, goog.events.EventType.RESIZE,
       this.updateSize, false, this);