Bluetooth: Protect pointers and callbacks

Test: kill com.android.bluetooth
Bug: 36150800
Change-Id: I9533731c9ce3776c84e6c1d3fdf3e266b328a084
diff --git a/bluetooth/1.0/default/bluetooth_hci.h b/bluetooth/1.0/default/bluetooth_hci.h
index 4f92231..6912405 100644
--- a/bluetooth/1.0/default/bluetooth_hci.h
+++ b/bluetooth/1.0/default/bluetooth_hci.h
@@ -44,8 +44,8 @@
 
  private:
   void sendDataToController(const uint8_t type, const hidl_vec<uint8_t>& data);
-  ::android::sp<IBluetoothHciCallbacks> event_cb_;
-  ::android::sp<BluetoothDeathRecipient> deathRecipient;
+  ::android::sp<BluetoothDeathRecipient> death_recipient_;
+  std::function<void(sp<BluetoothDeathRecipient>&)> unlink_cb_;
 };
 
 extern "C" IBluetoothHci* HIDL_FETCH_IBluetoothHci(const char* name);