Bluetooth: mac: add connected BLE devices at startup

device/bluetooth/test/bluetooth_test_mac.mm

Index: device/bluetooth/test/bluetooth_test_mac.mm
diff --git a/device/bluetooth/test/bluetooth_test_mac.mm b/device/bluetooth/test/bluetooth_test_mac.mm
index d7e6f4b63ad6020d8ebfeed19d13e4afb3bd52ee..bdb3eef5606dfde6d5abfa202e32429c22b3c7cb 100644
--- a/device/bluetooth/test/bluetooth_test_mac.mm
+++ b/device/bluetooth/test/bluetooth_test_mac.mm
@@ -144,6 +144,29 @@ explicit ScopedMockCentralManager(MockCentralManager* mock_central_manager) {
   }
 }
 
+void BluetoothTestMac::InitWithFakeAdapterWithConnectedLowEnergyDevice() {
+  MockCentralManager* mock_central_manager = [[MockCentralManager alloc] init];
+
+  scoped_nsobject<MockCBPeripheral> mock_peripheral([[MockCBPeripheral alloc]
+      initWithUTF8StringIdentifier:kTestPeripheralUUID1.c_str()
+                              name:@(kTestDeviceName.c_str())]);
+
+  mock_central_manager.connected_peripherals = @[ mock_peripheral.get() ];
+
+  mock_central_manager_.reset(
+      new ScopedMockCentralManager(mock_central_manager));
+
+  mock_central_manager_->get().bluetoothTestMac = this;
+  [mock_central_manager_->get() setState:CBCentralManagerStatePoweredOn];
+
+  adapter_mac_ =
+      BluetoothAdapterMac::CreateAdapterForTest(
+          kTestAdapterName, kTestAdapterAddress, message_loop_.task_runner(),
+          (id)mock_central_manager_->get())
+          .get();
+  adapter_ = adapter_mac_;
+}
+
 BluetoothDevice* BluetoothTestMac::SimulateLowEnergyDevice(int device_ordinal) {
   TestBluetoothAdapterObserver observer(adapter_);
   CBCentralManager* central_manager = adapter_mac_->low_energy_central_manager_;