NSNetServiceBrowser and NSNetService do not properly release the
delegates, see https://crbug.com/657495 and
https://openradar.appspot.com/
28943305
{
[_serviceBrowsers makeObjectsPerformSelector:@selector(stop)];
+ /* Work around a macOS 10.12 bug, see https://openradar.appspot.com/28943305 */
+ [_serviceBrowsers makeObjectsPerformSelector:@selector(setDelegate:) withObject:nil];
+ [_resolvedNetServices makeObjectsPerformSelector:@selector(setDelegate:) withObject:nil];
+
for (NSValue *item in _inputItemsForNetServices) {
if (_isRendererDiscovery) {
[self removeRawRendererItem:item];