Finishing: https://codereview.chromium.org/1948763003

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 0573c2fc11b8cb11d9e70db97c3c4e87b78518d8..dc36c2f382b28b651905db8d4cdbfd3493e8f6f7 100644
--- a/device/bluetooth/bluetooth_low_energy_device_mac.mm
+++ b/device/bluetooth/bluetooth_low_energy_device_mac.mm
@@ -322,15 +322,11 @@ BluetoothLowEnergyDeviceMac::GetBluetoothRemoteGattService(
 void BluetoothLowEnergyDeviceMac::DidDisconnectPeripheral(
     BluetoothDevice::ConnectErrorCode error_code) {
   SetGattServicesDiscoveryComplete(false);
-  // Explicitly take and erase GATT services one by one to ensure that calling
-  // GetGattService on removed service in GattServiceRemoved returns null.
-  std::vector<std::string> service_keys;
-  for (const auto& gatt_service : gatt_services_) {
-    service_keys.push_back(gatt_service.first);
-  }
-  for (const auto& key : service_keys) {
-    gatt_services_.take_and_erase(key);
-  }
+  // 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();
   if (create_gatt_connection_error_callbacks_.empty()) {
     // TODO(http://crbug.com/585897): Need to pass the error.
     DidDisconnectGatt();