Merge pull request #2647 from fredj/closure-lib-upgrade

Upgrade closure library version

src/ol/control/zoomslidercontrol.js

@@ -8,6 +8,7 @@ goog.require('goog.dom.TagName');
 goog.require('goog.events');
 goog.require('goog.events.Event');
 goog.require('goog.events.EventType');
+goog.require('goog.fx.DragDropEvent');
 goog.require('goog.fx.Dragger');
 goog.require('goog.fx.Dragger.EventType');
 goog.require('goog.math');

src/ol/map.js

@@ -265,8 +265,7 @@ ol.Map = function(options) {
     goog.events.EventType.TOUCHSTART,
     goog.events.EventType.MSPOINTERDOWN,
     ol.MapBrowserEvent.EventType.POINTERDOWN,
-    // see https://github.com/google/closure-library/pull/308
-    goog.userAgent.GECKO ? 'DOMMouseScroll' : 'mousewheel'
+    goog.events.EventType.MOUSEWHEEL
   ], goog.events.Event.stopPropagation);
   goog.dom.appendChild(this.viewport_, this.overlayContainerStopEvent_);