A tile queue that can be aborted.

This saves server requests, and because we use OpenLayers.Animation, setting img.src on a tile should not freeze iOS any more, so we can hopefully get rid of scheduleMoveGriddedTiles.

tests/deprecated/Layer/MapServer/Untiled.html

@@ -5,6 +5,11 @@
     <script src="../../../../lib/deprecated.js"></script>
     <script type="text/javascript">
 
+    // turn off animation frame handling, so we can check img urls in tests
+    OpenLayers.Layer.Grid.prototype.addTileOperation = function(fn, scope) {
+        fn.call(scope);
+    };
+
     var isMozilla = (navigator.userAgent.indexOf("compatible") == -1);
     var layer;