Remove outdated devices from Android device chooser

device/bluetooth/bluetooth_adapter_android.h

Index: device/bluetooth/bluetooth_adapter_android.h
diff --git a/device/bluetooth/bluetooth_adapter_android.h b/device/bluetooth/bluetooth_adapter_android.h
index c56914888a76c103184bb82e683116ed7a808146..0a34baf4bc3a30b3eae79923e13f33b8b9eb368e 100644
--- a/device/bluetooth/bluetooth_adapter_android.h
+++ b/device/bluetooth/bluetooth_adapter_android.h
@@ -128,9 +128,16 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapterAndroid final
   void RemovePairingDelegateInternal(
       BluetoothDevice::PairingDelegate* pairing_delegate) override;
 
+  void PurgeTimedOutDevices();
+
+  scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;
+
   // Java object org.chromium.device.bluetooth.ChromeBluetoothAdapter.
   base::android::ScopedJavaGlobalRef<jobject> j_adapter_;
 
+ private:
+  size_t num_discovery_sessions_ = 0;
+
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<BluetoothAdapterAndroid> weak_ptr_factory_;