New GoogleNG layer using tiles from the v3 API's mapType::getTile method. r=bartvde (closes #3312)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@12000 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Tile.js

@@ -103,7 +103,9 @@ OpenLayers.Tile = OpenLayers.Class({
         this.position = position.clone();
         this.bounds = bounds.clone();
         this.url = url;
-        this.size = size.clone();
+        if (size) {
+            this.size = size.clone();
+        }
 
         //give the tile a unique id based on its BBOX.
         this.id = OpenLayers.Util.createUniqueID("Tile_");