call layer.getImageSize with the tile bounds to support layer implementations

with different tile sizes at the extent edges. p=klokan, r=me (closes #2324)


git-svn-id: http://svn.openlayers.org/trunk/openlayers@9756 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer.js

@@ -555,12 +555,17 @@ OpenLayers.Layer = OpenLayers.Class({
     
     /**
      * APIMethod: getImageSize
+     *
+     * Parameters:
+     * bounds - {<OpenLayers.Bounds>} optional tile bounds, can be used
+     *     by subclasses that have to deal with different tile sizes at the
+     *     layer extent edges (e.g. Zoomify)
      * 
      * Returns:
      * {<OpenLayers.Size>} The size that the image should be, taking into 
      *     account gutters.
      */ 
-    getImageSize: function() { 
+    getImageSize: function(bounds) { 
         return (this.imageSize || this.tileSize); 
     },