Change record status: 
Project: 
Introduced in branch: 
8.x
Description: 

Before

$element_info = element_info('submit');
$element_info_property = element_info_property($type, $property_name, $default); 

After

$element_info = \Drupal::service('element_info')->getInfo('submit');
$element_info_property = \Drupal::service('element_info')->getInfoProperty('submit','#process',[]); 
Impacts: 
Module developers
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done