[Bug 826278] Fixed bookmark icon bug [r=crdlc]

In Evme, relevant grid apps appear on top of results. Bookmarks didn't show the correct icon (defaulted). https://bug826278.bugzilla.mozilla.org/attachment.cgi?id=697483

Now using GridManager.getIcon instead of GridManager.getIconsForApp, the correct image appears.

https://bugzilla.mozilla.org/show_bug.cgi?id=826278