fix: crash in AutofillPopup teardown (#51302)
Fix a crash in AutofillPopupView::Show() when the popup
tried to show itself after the parent's native view had
already gone away during teardown.
2026-04-23T20:44:32.7015810Z Received signal 11 SEGV_ACCERR 000000000160
2026-04-23T20:44:32.9322010Z 4 Electron Framework ... views::Widget::IsVisible() const + 28
2026-04-23T20:44:32.9528810Z 6 Electron Framework ... electron::AutofillPopupView::Show() + 200
2026-04-23T20:44:32.9632090Z 7 Electron Framework ... electron::AutofillPopup::CreateView(...) + 1380
2026-04-23T20:44:32.9749770Z 8 Electron Framework ... electron::AutofillDriver::ShowAutofillPopup(...) + 736
2026-04-23T20:44:33.0015220Z ✗ Electron tests failed with kill signal SIGSEGV.
Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>