Layer for demo.

src/ol/layer/OSM.js

@@ -0,0 +1,16 @@
+goog.provide('ol.layer.OSM');
+
+goog.require('ol.layer.XYZ');
+
+/**
+ * Class for OSM layers.
+ *
+ * @export
+ * @constructor
+ * @extends {ol.layer.XYZ}
+ */
+ol.layer.OSM = function() { 
+    goog.base(this, 'http://a.tile.openstreetmap.org/{z}/{x}/{y}.png');
+};
+
+goog.inherits(ol.layer.OSM, ol.layer.XYZ);