bluetooth: Call error callback when characteristics get destroyed during a GATT Event (mac)

device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm

Index: device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm
diff --git a/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm b/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm
index ffa4ad601678c1ef63e5d64d42da5f7acea87141..047cb80a9334e2d38d2b9157aec697f5ed32a8ef 100644
--- a/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm
+++ b/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm
@@ -80,7 +80,18 @@ BluetoothRemoteGattCharacteristicMac::BluetoothRemoteGattCharacteristicMac(
                                  (void*)cb_characteristic_]);
 }
 
-BluetoothRemoteGattCharacteristicMac::~BluetoothRemoteGattCharacteristicMac() {}
+BluetoothRemoteGattCharacteristicMac::~BluetoothRemoteGattCharacteristicMac() {
+  if (!read_characteristic_value_callbacks_.first.is_null()) {
+    std::pair<ValueCallback, ErrorCallback> callbacks;
+    callbacks.swap(read_characteristic_value_callbacks_);
+    callbacks.second.Run(BluetoothGattService::GATT_ERROR_FAILED);
+  }
+  if (!write_characteristic_value_callbacks_.first.is_null()) {
+    std::pair<base::Closure, ErrorCallback> callbacks;
+    callbacks.swap(write_characteristic_value_callbacks_);
+    callbacks.second.Run(BluetoothGattService::GATT_ERROR_FAILED);
+  }
+}
 
 std::string BluetoothRemoteGattCharacteristicMac::GetIdentifier() const {
   return identifier_;