Use goog.DEBUG instead of ol.DEBUG for now

src/ol/renderer/canvas/canvasimagelayerrenderer.js

@@ -162,7 +162,7 @@ ol.renderer.canvas.ImageLayer.prototype.prepareFrame = function(frameState, laye
     if (!ol.ENABLE_RASTER_REPROJECTION) {
       var sourceProjection = imageSource.getProjection();
       if (sourceProjection) {
-        ol.DEBUG && console.assert(ol.proj.equivalent(projection, sourceProjection),
+        goog.DEBUG && console.assert(ol.proj.equivalent(projection, sourceProjection),
             'projection and sourceProjection are equivalent');
         projection = sourceProjection;
       }

src/ol/renderer/canvas/canvasmaprenderer.js

@@ -82,7 +82,7 @@ ol.renderer.canvas.Map.prototype.createLayerRenderer = function(layer) {
   } else if (ol.ENABLE_VECTOR && layer instanceof ol.layer.Vector) {
     return new ol.renderer.canvas.VectorLayer(layer);
   } else {
-    ol.DEBUG && console.assert(false, 'unexpected layer configuration');
+    goog.DEBUG && console.assert(false, 'unexpected layer configuration');
     return null;
   }
 };

src/ol/renderer/canvas/canvastilelayerrenderer.js

@@ -142,7 +142,7 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame = function(
       if (!drawableTile(tile) && tile.interimTile) {
         tile = tile.interimTile;
       }
-      ol.DEBUG && console.assert(tile);
+      goog.DEBUG && console.assert(tile);
       if (drawableTile(tile)) {
         tilesToDrawByZ[z][tile.tileCoord.toString()] = tile;
         continue;

src/ol/renderer/canvas/canvasvectorlayerrenderer.js

@@ -172,7 +172,7 @@ ol.renderer.canvas.VectorLayer.prototype.forEachFeatureAtCoordinate = function(c
          * @return {?} Callback result.
          */
         function(feature) {
-          ol.DEBUG && console.assert(feature !== undefined, 'received a feature');
+          goog.DEBUG && console.assert(feature !== undefined, 'received a feature');
           var key = ol.getUid(feature).toString();
           if (!(key in features)) {
             features[key] = true;

src/ol/renderer/canvas/canvasvectortilelayerrenderer.js

@@ -306,7 +306,7 @@ ol.renderer.canvas.VectorTileLayer.prototype.forEachFeatureAtCoordinate = functi
          * @return {?} Callback result.
          */
         function(feature) {
-          ol.DEBUG && console.assert(feature, 'received a feature');
+          goog.DEBUG && console.assert(feature, 'received a feature');
           var key = ol.getUid(feature).toString();
           if (!(key in features)) {
             features[key] = true;