Allow device/bluetooth to build on the macOS 10.13 SDK

device/bluetooth/bluetooth_low_energy_device_mac.mm

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "device/bluetooth/bluetooth_low_energy_device_mac.h"
 
 #import <CoreFoundation/CoreFoundation.h>
 #include <stddef.h>
 
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/sdk_forward_declarations.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/sys_string_conversions.h"
 #include "device/bluetooth/bluetooth_adapter_mac.h"
 #include "device/bluetooth/bluetooth_device.h"
 #include "device/bluetooth/bluetooth_low_energy_peripheral_delegate.h"
 #include "device/bluetooth/bluetooth_remote_gatt_characteristic_mac.h"
 #include "device/bluetooth/bluetooth_remote_gatt_descriptor_mac.h"
 #include "device/bluetooth/bluetooth_remote_gatt_service_mac.h"
 
+// Remove when Chrome no longer supports 10.12.
+#if defined(MAC_OS_X_VERSION_10_13)
+
+// In the 10.13 SDK, CBPeripheral became a subclass of CBPeer, which defines
+// -[CBPeer identifier] as partially available. Pretend it still exists on
+// CBPeripheral. At runtime the implementation on CBPeer will be invoked.
+@interface CBPeripheral (HighSierraSDK)
+@property(readonly, nonatomic) NSUUID* identifier;
+@end
+
+#endif  // MAC_OS_X_VERSION_10_13
+
 namespace device {
 
 BluetoothLowEnergyDeviceMac::BluetoothLowEnergyDeviceMac(
     BluetoothAdapterMac* adapter,
     CBPeripheral* peripheral)
     : BluetoothDeviceMac(adapter),
       peripheral_(peripheral, base::scoped_policy::RETAIN),
       connected_(false),
       discovery_pending_count_(0) {
   DCHECK(BluetoothAdapterMac::IsLowEnergyAvailable());
@@ skipping 477 matching lines @@
   // BluetoothLowEnergyDeviceMac::GetNameForDisplay() instead.
   base::Optional<std::string> name = device.GetName();
   const char* is_gatt_connected =
       device.IsGattConnected() ? "GATT connected" : "GATT disconnected";
   return out << "<BluetoothLowEnergyDeviceMac " << device.GetAddress() << "/"
              << &device << ", " << is_gatt_connected << ", \""
              << name.value_or("Unnamed device") << "\">";
 }
 
 }  // namespace device