This allows us to test the infrastructure for presenting dialogs that don't take up the entire screen.
- Group Reviewers
O2: Material Motion O4: Material Apple platform reviewers Material Motion
- R50:c60fedb74033: Minor cleanup.
R50:e12d1479bbb2: Flexible margins when presenting a modal dialog.
R50:1ef994decb75: Add a switch for toggling whether the presented view controller should be…