Merge pull request #1019 from ahocevar/chrome-optimized

Deal with recent Chrome optimizations to avoid failing TileManager and tests

lib/OpenLayers/Tile/Image.js

@@ -314,11 +314,17 @@ OpenLayers.Tile.Image = OpenLayers.Class(OpenLayers.Tile, {
      * Creates the content for the frame on the tile.
      */
     initImage: function() {
+        if (!this.url && !this.imgDiv) {
+            // fast path out - if there is no tile url and no previous image
+            this.isLoading = false;
+            return;
+        }
         this.events.triggerEvent('beforeload');
         this.layer.div.appendChild(this.getTile());
         this.events.triggerEvent(this._loadEvent);
         var img = this.getImage();
-        if (this.url && OpenLayers.Util.isEquivalentUrl(img.src, this.url)) {
+        var src = img.getAttribute('src') || '';
+        if (this.url && OpenLayers.Util.isEquivalentUrl(src, this.url)) {
             this._loadTimeout = window.setTimeout(
                 OpenLayers.Function.bind(this.onImageLoad, this), 0
             );