$this
`$this` is a pseudo-variable that cannot be used as the name of a function parameter, so renaming these helps prevent errors when implementing hook callback functions. Fixes #53457 Built from https://develop.svn.wordpress.org/trunk@51518 git-svn-id: http://core.svn.wordpress.org/trunk@51129 1a063a9b-81f0-0310-95a4-ce76da25c4cd
$type
$mime_type
WP_Customize_Image_Control
/
$button_labels
WP_Customize_Upload_Control
@since
class-wp-widget-area-customize-control.php