Submit handler to delete a display from a view.
public function submitDisplayDelete($form, &$form_state) {
$view = $this
->getEntity($form_state);
$display_id = $form_state['display_id'];
// Mark the display for deletion.
$displays = $view
->get('display');
$displays[$display_id]['deleted'] = TRUE;
$view
->set('display', $displays);
views_ui_cache_set($view);
// Redirect to the top-level edit page. The first remaining display will
// become the active display.
$form_state['redirect'] = 'admin/structure/views/view/' . $view
->get('name');
}