Fix tests for when not run with WebGL support

src/ol/style/atlasmanager.js

@@ -30,7 +30,7 @@ ol.style.AtlasManagerInfo;
  * atlas. After that, when new atlases are created, they will have
  * twice the size as the latest atlas (until `maxSize` is reached).
  *
- * If an application uses a lot, or a lot of large images, it is recommend to
+ * If an application uses a lot, or a lot of large images, it is recommended to
  * set a higher `size` value to avoid the creation of too many atlases.
  *
  * @constructor

src/ol/style/regularshapestyle.js

@@ -322,7 +322,7 @@ ol.style.RegularShape.prototype.render_ = function(atlasManager) {
     var info = atlasManager.add(
         id, size, size, goog.bind(this.draw_, this, renderOptions),
         renderHitDetectionCallback);
-    goog.asserts.assert(info !== null, 'shape size is too large');
+    goog.asserts.assert(!goog.isNull(info), 'shape size is too large');
 
     this.canvas_ = info.image;
     this.origin_ = [info.offsetX, info.offsetY];

src/ol/webgl/context.js

@@ -5,6 +5,7 @@ goog.require('goog.asserts');
 goog.require('goog.events');
 goog.require('goog.log');
 goog.require('goog.object');
+goog.require('ol');
 goog.require('ol.webgl.Buffer');
 goog.require('ol.webgl.WebGLContextEventType');