examples `chaos_game` and `threads` not building, winit unresolved imports

In trying to track down a Metal issue with pathfinder, I'm trying to build and run the demos here.
The offscreen demo builds and runs fine, but the chaos_game and threads demos both fail with the same compile errors:

   Compiling surfman v0.4.3 (/Users/.../surfman/surfman)
error[E0432]: unresolved imports `winit::DeviceEvent`, `winit::Event`, `winit::EventsLoop`, `winit::KeyboardInput`, `winit::VirtualKeyCode`
 --> surfman/examples/chaos_game.rs:9:13
  |
9 | use winit::{DeviceEvent, Event, EventsLoop, KeyboardInput, VirtualKeyCode};
  |             ^^^^^^^^^^^  ^^^^^  ^^^^^^^^^^  ^^^^^^^^^^^^^  ^^^^^^^^^^^^^^ no `VirtualKeyCode` in the root
  |             |            |      |           |
  |             |            |      |           no `KeyboardInput` in the root
  |             |            |      no `EventsLoop` in the root
  |             |            no `Event` in the root
  |             no `DeviceEvent` in the root

error[E0432]: unresolved imports `winit::WindowBuilder`, `winit::WindowEvent`
  --> surfman/examples/chaos_game.rs:10:13
   |
10 | use winit::{WindowBuilder, WindowEvent};
   |             ^^^^^^^^^^^^^  ^^^^^^^^^^^ no `WindowEvent` in the root
   |             |
   |             no `WindowBuilder` in the root

This is on macOS 12.1, rustc 1.58.0.

Start with surfman/examples/chaos_game.rs and the corresponding threads example, focusing on the unresolved winit imports shown in the report. Check the winit dependency and API used by both demos, then verify that the chaos_game and threads examples build successfully on the reported Rust setup.