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..db28fb9df011cd396d3b02e91cee3369fc45dede 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_;
@@ -249,6 +260,7 @@ void BluetoothRemoteGattCharacteristicMac::UnsubscribeFromNotifications(
 }
 
 void BluetoothRemoteGattCharacteristicMac::DidUpdateValue(NSError* error) {
+  CHECK_EQ(gatt_service_->GetCBPeripheral().state, CBPeripheralStateConnected);
   // This method is called when the characteristic is read and when a
   // notification is received.
   if (characteristic_value_read_or_write_in_progress_) {
@@ -285,6 +297,7 @@ void BluetoothRemoteGattCharacteristicMac::UpdateValueAndNotify() {
 }
 
 void BluetoothRemoteGattCharacteristicMac::DidWriteValue(NSError* error) {
+  CHECK_EQ(gatt_service_->GetCBPeripheral().state, CBPeripheralStateConnected);
   if (!characteristic_value_read_or_write_in_progress_) {
     // In case of buggy device, nothing should be done if receiving extra
     // write confirmation.