Bug 417952 - Open Containing Folder doesn't highlight/select file in Nautilus. r=karlt

If the File Manager DBus Interface[1] is present, use it to
launch file manager and select the file, otherwise fallback to
existing code for backwards compatibility.

[1] http://www.freedesktop.org/wiki/Specifications/file-manager-interface/

xpcom/io/nsLocalFileUnix.cpp

@@ -1782,6 +1782,8 @@ nsLocalFile::Reveal()
         else 
             /* Fallback to GnomeVFS */
             return gnomevfs->ShowURIForInput(mPath);
+    } else if (giovfs && NS_SUCCEEDED(giovfs->OrgFreedesktopFileManager1ShowItems(mPath))) {
+        return NS_OK;
     } else {
         nsCOMPtr<nsIFile> parentDir;
         nsAutoCString dirPath;