bluetoothLowEnergy: Send onServiceAdded after all characteristics are discovered

chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc

Index: chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc
diff --git a/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc b/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc
index 04745e6ce79af8eb0c3040469339e0afb6dbe3b7..3567567271c9dcebd7addb5b2ed61f7e67803c39 100644
--- a/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc
+++ b/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.cc
@@ -294,6 +294,11 @@ void FakeBluetoothGattCharacteristicClient::ExposeHeartRateCharacteristics(
           kClientCharacteristicConfigurationUUID));
   DCHECK(ccc_path.IsValid());
   heart_rate_measurement_ccc_desc_path_ = ccc_path.value();
+
+  std::vector<dbus::ObjectPath> desc_paths;
+  desc_paths.push_back(ccc_path);
+
+  heart_rate_measurement_properties_->descriptors.ReplaceValue(desc_paths);
 }
 
 void FakeBluetoothGattCharacteristicClient::HideHeartRateCharacteristics() {