Several classes retain callbacks while asynchronous operations are pending. In the event of the instances being destroyed the callbacks are not called, but they should be.

E.g.

BluetoothRemoteGattCharacteristicAndroid::
    ~BluetoothRemoteGattCharacteristicAndroid() {
...
  if (pending_start_notify_calls_.size()) {
    OnStartNotifySessionError(device::BluetoothGattService::GATT_ERROR_FAILED);
  }
}