Bug 721582 - We should probably use a strong assert for target in...

  // Dispatch it to the background

  nsIEventTarget *target = aConnection->getAsyncExecutionTarget();

  NS_ENSURE_TRUE(target, NS_ERROR_NOT_AVAILABLE);

  // If we don't have a valid target, this is a bug somewhere else. In the past,

  // this assert found cases where a Run method would schedule a new statement

  // without checking if asyncClose had been called. The caller must prevent

  // that from happening or, if the work is not critical, just avoid creating

  // the new statement during shutdown. See bug 718449 for an example.

  MOZ_ASSERT(target);

  if (!target) {

    return NS_ERROR_NOT_AVAILABLE;

  }

  nsresult rv = target->Dispatch(event, NS_DISPATCH_NORMAL);

  NS_ENSURE_SUCCESS(rv, rv);