Set Header on XHProf ObjectBox

Summary: Third times the charm?

Test Plan: pray

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11816

src/applications/xhprof/view/PhabricatorXHProfProfileTopLevelView.php

@@ -133,6 +133,7 @@ final class PhabricatorXHProfProfileTopLevelView
       $header->addActionLink($button);
     }
 
+    $panel->setHeader($header);
     $panel->appendChild($table);
 
     return $panel->render();