WebUI: fix error in Grid.getItemsInViewPort preventing correct layout.

BUG=chromium-os:24015
TEST=Manual: see bug description; all grids in WebUI should be layout properly.


Review URL: http://codereview.chromium.org/8923001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@114279 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/shared/js/cr/ui/grid.js

@@ -168,7 +168,11 @@ cr.define('cr.ui', function() {
           this.countItemsInRange_(firstIndex, scrollTop + clientHeight));
       count = columns * Math.ceil(count / columns);
       count = Math.min(count, this.dataModel.length - firstIndex);
-      return count;
+      return {
+        first: firstIndex,
+        length: count,
+        last: firstIndex + count - 1
+      };
     },
 
     /**