void OmniboxEditModel::OnKillFocus() {
  SetFocusState(OMNIBOX_FOCUS_NONE, OMNIBOX_FOCUS_CHANGE_EXPLICIT);
  focus_source_ = INVALID;
  control_key_state_ = UP;
  paste_state_ = NONE;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.