asynctypes-685526: helpers tidy-up after run
asynctypes-685526: helpers tidy-up after run

2 changes:
- Add options.document because it's just as useful as options.window
  and it's hard to remember which is available
- Remove the properties added when the test has run.

Signed-off-by: Joe Walker <7a17872fbb32c7d760c9a16ee3076daead11efcf@mozilla.com>

joewalker/gcli,mozilla/gcli,joewalker/gcli,mozilla/gcli,mozilla/gcli