* fix: re-enable the spellchecker when new language list set
Chromium recently added prefs logic to disable the spellchecker if the list of languages is empty, but the logic to re-enable if the languages are provided again lives in another part of Chromium. This change makes it so our API re-enables the spellchecker correctly when required.
* chore: fix lint
* fix: emit updated on NativeTheme on the UI thread to avoid DCHECK
* Update atom_api_native_theme.cc
* spec: wait a few ticks for async events to emit so that test events do not leak into each other
