TileManager dependency management

If the build does not contain TileManager.js, do not create a TileManager
instance for the map. If the build does not contain Layer/Grid.js, do not
try to add Grid layer instances to the list of layers managed by the
TileManager.

lib/OpenLayers/Map.js

@@ -10,7 +10,6 @@
  * @requires OpenLayers/Events.js
  * @requires OpenLayers/Tween.js
  * @requires OpenLayers/Projection.js
- * @requires OpenLayers/TileManager.js
  */
 
 /**
@@ -376,11 +375,12 @@ OpenLayers.Map = OpenLayers.Class({
 
     /**
      * APIProperty: tileManager
-     * {<OpenLayers.TileManager>|Object} By default the map will use the TileManager
+     * {<OpenLayers.TileManager>|Object} By default, and if the build contains
-     * to queue image requests and to cache tile image elements. To create a
+     * TileManager.js, the map will use the TileManager to queue image requests
-     * map without a TileManager configure the map with tileManager: null.
+     * and to cache tile image elements. To create a map without a TileManager
-     * To create a TileManager with non-default options, supply the options
+     * configure the map with tileManager: null. To create a TileManager with
-     * instead or alternatively supply an instance of {<OpenLayers.TileManager>}.
+     * non-default options, supply the options instead or alternatively supply
+     * an instance of {<OpenLayers.TileManager>}.
      */
 
     /**
@@ -615,7 +615,8 @@ OpenLayers.Map = OpenLayers.Class({
         );
         
         if (this.tileManager !== null) {
-            if (!(this.tileManager instanceof OpenLayers.TileManager)) {
+            if (OpenLayers.TileManager &&
+                  !(this.tileManager instanceof OpenLayers.TileManager)) {
                 this.tileManager = new OpenLayers.TileManager(this.tileManager);
             }
             this.tileManager.addMap(this);

lib/OpenLayers/TileManager.js

@@ -5,7 +5,6 @@
 
 
 /**
- * @requires OpenLayers/Layer/Grid.js
  * @requires OpenLayers/Util.js
  * @requires OpenLayers/BaseTypes.js
  * @requires OpenLayers/BaseTypes/Element.js
@@ -117,7 +116,7 @@ OpenLayers.TileManager = OpenLayers.Class({
      * map - {<OpenLayers.Map>}
      */
     addMap: function(map) {
-        if (this._destroyed) {
+        if (this._destroyed || !OpenLayers.Layer.Grid) {
             return;
         }
         this.maps.push(map);
@@ -143,7 +142,7 @@ OpenLayers.TileManager = OpenLayers.Class({
      * map - {<OpenLayers.Map>}
      */
     removeMap: function(map) {
-        if (this._destroyed) {
+        if (this._destroyed || !OpenLayers.Layer.Grid) {
             return;
         }
         window.clearTimeout(this.tileQueueId[map.id]);