Replace goog.isDefAndNotNull() with truthy checks

src/ol/format/gml/gmlbaseformat.js

@@ -180,7 +180,7 @@ ol.format.GMLBase.prototype.readGeometryElement = function(node, objectStack) {
   context['srsName'] = node.firstElementChild.getAttribute('srsName');
   var geometry = ol.xml.pushParseAndPop(/** @type {ol.geom.Geometry} */(null),
       this.GEOMETRY_PARSERS_, node, objectStack, this);
-  if (goog.isDefAndNotNull(geometry)) {
+  if (geometry) {
     return /** @type {ol.geom.Geometry} */ (
         ol.format.Feature.transformWithOptions(geometry, false, context));
   } else {
@@ -243,7 +243,7 @@ ol.format.GMLBase.prototype.readPoint = function(node, objectStack) {
   goog.asserts.assert(node.localName == 'Point', 'localName should be Point');
   var flatCoordinates =
       this.readFlatCoordinatesFromNode_(node, objectStack);
-  if (goog.isDefAndNotNull(flatCoordinates)) {
+  if (flatCoordinates) {
     var point = new ol.geom.Point(null);
     goog.asserts.assert(flatCoordinates.length == 3,
         'flatCoordinates should have a length of 3');
@@ -382,7 +382,7 @@ ol.format.GMLBase.prototype.readLineString = function(node, objectStack) {
       'localName should be LineString');
   var flatCoordinates =
       this.readFlatCoordinatesFromNode_(node, objectStack);
-  if (goog.isDefAndNotNull(flatCoordinates)) {
+  if (flatCoordinates) {
     var lineString = new ol.geom.LineString(null);
     lineString.setFlatCoordinates(ol.geom.GeometryLayout.XYZ, flatCoordinates);
     return lineString;
@@ -406,7 +406,7 @@ ol.format.GMLBase.prototype.readFlatLinearRing_ = function(node, objectStack) {
   var ring = ol.xml.pushParseAndPop(/** @type {Array.<number>} */(null),
       this.GEOMETRY_FLAT_COORDINATES_PARSERS_, node,
       objectStack, this);
-  if (goog.isDefAndNotNull(ring)) {
+  if (ring) {
     return ring;
   } else {
     return undefined;