Bluetooth: macOS: Adding counter for service discovery callbacks.

device/bluetooth/test/bluetooth_test_mac.h

Index: device/bluetooth/test/bluetooth_test_mac.h
diff --git a/device/bluetooth/test/bluetooth_test_mac.h b/device/bluetooth/test/bluetooth_test_mac.h
index daa0d4671b58e7b836e9c1691e260007b9e92f00..3dd04f82d30ae097aa8afdaa57ede1e49eaf27c7 100644
--- a/device/bluetooth/test/bluetooth_test_mac.h
+++ b/device/bluetooth/test/bluetooth_test_mac.h
@@ -94,6 +94,7 @@ class BluetoothTestMac : public BluetoothTestBase {
 
   // Callback for the bluetooth peripheral mock.
   void OnFakeBluetoothServiceDiscovery();
+  void OnFakeBluetoothCharacteristicDiscovery();
   void OnFakeBluetoothCharacteristicReadValue();
   void OnFakeBluetoothCharacteristicWriteValue(std::vector<uint8_t> value);
   void OnFakeBluetoothGattSetCharacteristicNotification(bool notify_value);
@@ -124,6 +125,7 @@ class BluetoothTestMac : public BluetoothTestBase {
 
   // Value set by -[CBPeripheral setNotifyValue:forCharacteristic:] call.
   bool last_notify_value_ = false;
+  int gatt_characteristic_discovery_attempts_ = 0;
 };
 
 // Defines common test fixture name. Use TEST_F(BluetoothTest, YourTestName).