- Fix "page closed twice" race.
- Do not fire 'disconnected' on swapped out sessions.
- Use a different error for commands sent to swapped out targets.
This allows callers to detect this situation and retry/throw/catch.
- Restore more state on swap: extra http headers, user agent, emulated media.
This makes it so that JSHandles and ElementHandles are aware of what types they point to. As a fun bonus, `$eval('input')` knows its going to get an HTMLInputElement.
Most of this patch is casting things where previously we just assumed ElementHandles held the right kind of node. This gets us closer to being able to turn on `noImplicityAny` as well.
#6
