Revert of Bluetooth: mac: Crash while loging nil error.

device/bluetooth/bluetooth_low_energy_device_mac.mm

Index: device/bluetooth/bluetooth_low_energy_device_mac.mm
diff --git a/device/bluetooth/bluetooth_low_energy_device_mac.mm b/device/bluetooth/bluetooth_low_energy_device_mac.mm
index 8b56d51bb661cdeb732985d92f8b9f41feda4387..0db9ce10233571d642f9c29ee3050faecdf8b970 100644
--- a/device/bluetooth/bluetooth_low_energy_device_mac.mm
+++ b/device/bluetooth/bluetooth_low_energy_device_mac.mm
@@ -390,13 +390,18 @@
   return nullptr;
 }
 
-void BluetoothLowEnergyDeviceMac::DidDisconnectPeripheral() {
+void BluetoothLowEnergyDeviceMac::DidDisconnectPeripheral(
+    BluetoothDevice::ConnectErrorCode error_code) {
   SetGattServicesDiscoveryComplete(false);
   // Removing all services at once to ensure that calling GetGattService on
   // removed service in GattServiceRemoved returns null.
   GattServiceMap gatt_services_swapped;
   gatt_services_swapped.swap(gatt_services_);
   gatt_services_swapped.clear();
-  DCHECK(create_gatt_connection_error_callbacks_.empty());
-  DidDisconnectGatt();
-}
+  if (create_gatt_connection_error_callbacks_.empty()) {
+    // TODO(http://crbug.com/585897): Need to pass the error.
+    DidDisconnectGatt();
+  } else {
+    DidFailToConnectGatt(error_code);
+  }
+}