Inline goog.isDef() property checks

src/ol/renderer/canvas/canvasimagelayerrenderer.js

@@ -163,7 +163,7 @@ ol.renderer.canvas.ImageLayer.prototype.prepareFrame =
   var hints = frameState.viewHints;
 
   var renderedExtent = frameState.extent;
-  if (goog.isDef(layerState.extent)) {
+  if (layerState.extent !== undefined) {
     renderedExtent = ol.extent.getIntersection(
         renderedExtent, layerState.extent);
   }

src/ol/renderer/canvas/canvastilelayerrenderer.js

@@ -217,7 +217,7 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame =
     extent = frameState.extent;
   }
 
-  if (goog.isDef(layerState.extent)) {
+  if (layerState.extent !== undefined) {
     extent = ol.extent.getIntersection(extent, layerState.extent);
   }
   if (ol.extent.isEmpty(extent)) {

src/ol/renderer/dom/domimagelayerrenderer.js

@@ -94,7 +94,7 @@ ol.renderer.dom.ImageLayer.prototype.prepareFrame =
   var hints = frameState.viewHints;
 
   var renderedExtent = frameState.extent;
-  if (goog.isDef(layerState.extent)) {
+  if (layerState.extent !== undefined) {
     renderedExtent = ol.extent.getIntersection(
         renderedExtent, layerState.extent);
   }

src/ol/renderer/dom/domtilelayerrenderer.js

@@ -119,7 +119,7 @@ ol.renderer.dom.TileLayer.prototype.prepareFrame =
     extent = frameState.extent;
   }
 
-  if (goog.isDef(layerState.extent)) {
+  if (layerState.extent !== undefined) {
     extent = ol.extent.getIntersection(extent, layerState.extent);
   }
 

src/ol/renderer/webgl/webglimagelayerrenderer.js

@@ -118,7 +118,7 @@ ol.renderer.webgl.ImageLayer.prototype.prepareFrame =
   var hints = frameState.viewHints;
 
   var renderedExtent = frameState.extent;
-  if (goog.isDef(layerState.extent)) {
+  if (layerState.extent !== undefined) {
     renderedExtent = ol.extent.getIntersection(
         renderedExtent, layerState.extent);
   }

src/ol/renderer/webgl/webgltilelayerrenderer.js

@@ -251,7 +251,7 @@ ol.renderer.webgl.TileLayer.prototype.prepareFrame =
       for (y = tileRange.minY; y <= tileRange.maxY; ++y) {
 
         tile = tileSource.getTile(z, x, y, pixelRatio, projection);
-        if (goog.isDef(layerState.extent)) {
+        if (layerState.extent !== undefined) {
           // ignore tiles outside layer extent
           tileExtent = tileGrid.getTileCoordExtent(tile.tileCoord, tmpExtent);
           if (!ol.extent.intersects(tileExtent, layerState.extent)) {