Remove use of goog.array.sort

Fixes #4160

src/ol/renderer/canvas/canvastilelayerrenderer.js

@@ -3,7 +3,6 @@
 
 goog.provide('ol.renderer.canvas.TileLayer');
 
-goog.require('goog.array');
 goog.require('goog.asserts');
 goog.require('goog.vec.Mat4');
 goog.require('ol.Size');
@@ -365,7 +364,7 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame =
 
   /** @type {Array.<number>} */
   var zs = Object.keys(tilesToDrawByZ).map(Number);
-  goog.array.sort(zs);
+  zs.sort();
   var opaque = tileSource.getOpaque();
   var origin = ol.extent.getTopLeft(tileGrid.getTileCoordExtent(
       [z, canvasTileRange.minX, canvasTileRange.maxY],

src/ol/renderer/canvas/canvasvectorlayerrenderer.js

@@ -1,6 +1,5 @@
 goog.provide('ol.renderer.canvas.VectorLayer');
 
-goog.require('goog.array');
 goog.require('goog.asserts');
 goog.require('goog.events');
 goog.require('ol.ViewHint');
@@ -300,7 +299,7 @@ ol.renderer.canvas.VectorLayer.prototype.prepareFrame =
         function(feature) {
           features.push(feature);
         }, this);
-    goog.array.sort(features, vectorLayerRenderOrder);
+    features.sort(vectorLayerRenderOrder);
     features.forEach(renderFeature, this);
   } else {
     vectorSource.forEachFeatureInExtent(extent, renderFeature, this);