DOM renderer should re-render when layers are added or removed

src/ol/renderer/dom/dommaprenderer.js

@@ -48,6 +48,15 @@ ol.renderer.dom.Map = function(container, map) {
 goog.inherits(ol.renderer.dom.Map, ol.renderer.Map);
 
 
+/**
+ * @inheritDoc
+ */
+ol.renderer.dom.Map.prototype.addLayer = function(layer) {
+  goog.base(this, 'addLayer', layer);
+  this.getMap().render();
+};
+
+
 /**
  * @inheritDoc
  */
@@ -63,6 +72,15 @@ ol.renderer.dom.Map.prototype.createLayerRenderer = function(layer) {
 };
 
 
+/**
+ * @inheritDoc
+ */
+ol.renderer.dom.Map.prototype.removeLayer = function(layer) {
+  goog.base(this, 'removeLayer', layer);
+  this.getMap().render();
+};
+
+
 /**
  * @inheritDoc
  */