Add missing requires

Without explicit requires, it is possible that a build would exclude ol.js.

src/ol/renderer/canvas/canvasmaprenderer.js

@@ -6,6 +6,7 @@ goog.require('goog.asserts');
 goog.require('goog.dom');
 goog.require('goog.style');
 goog.require('goog.vec.Mat4');
+goog.require('ol');
 goog.require('ol.css');
 goog.require('ol.dom');
 goog.require('ol.layer.Image');

src/ol/renderer/dom/dommaprenderer.js

@@ -5,6 +5,7 @@ goog.require('goog.dom');
 goog.require('goog.dom.TagName');
 goog.require('goog.functions');
 goog.require('goog.style');
+goog.require('ol');
 goog.require('ol.css');
 goog.require('ol.layer.Image');
 goog.require('ol.layer.Tile');

src/ol/renderer/dom/domtilelayerrenderer.js

@@ -10,6 +10,7 @@ goog.require('goog.dom.TagName');
 goog.require('goog.object');
 goog.require('goog.style');
 goog.require('goog.vec.Mat4');
+goog.require('ol');
 goog.require('ol.Coordinate');
 goog.require('ol.Tile');
 goog.require('ol.TileCoord');

src/ol/renderer/webgl/webglmaprenderer.js

@@ -13,6 +13,7 @@ goog.require('goog.log.Logger');
 goog.require('goog.object');
 goog.require('goog.style');
 goog.require('goog.webgl');
+goog.require('ol');
 goog.require('ol.Tile');
 goog.require('ol.css');
 goog.require('ol.dom');