$this->buttons = '<div>';
$this->buttons .= $this->submitButton( wfMsg( 'compareselectedversions' ),
array( 'class' => 'historysubmit' )
- + $wgUser->getSkin()->tooltipAndAccessKeyAttribs( 'compareselectedversions' )
+ + Linker::tooltipAndAccesskeyAttribs( 'compareselectedversions' )
) . "\n";
if ( $wgUser->isAllowed( 'deleterevision' ) ) {