adding comment that the reproject option is deprecated and getBoundsFromLayer is defined in deprecated.js, as suggested by @elemoine.

Author: ahocevar

lib/OpenLayers/Tile/Image.js

@@ -136,7 +136,9 @@ OpenLayers.Tile.Image = OpenLayers.Class(OpenLayers.Tile, {
     draw: function() {
         var drawn = OpenLayers.Tile.prototype.draw.apply(this, arguments);
         if (drawn) {
+            // The layer's reproject option is deprecated.
             if (this.layer != this.layer.map.baseLayer && this.layer.reproject) {
+                // getBoundsFromBaseLayer is defined in deprecated.js.
                 this.bounds = this.getBoundsFromBaseLayer(this.position);
             }
             if (this.isLoading) {