* Electron version: 1.4.4
* Operating system: win10

Hi,
Example described [here](https://github.com/electron/electron/blob/master/docs/api/global-shortcut.md) works with v1.4.0 but doesn't seem to work with v1.4.4 or v1.4.5.  Method `globalShortcut.isRegistered ` returns true, but the callback isn't called. 

Thanks!
atom/browser/api/atom_api_system_preferences.cc
.SetMethod("unsubscribeNotification",
                 &SystemPreferences::UnsubscribeNotification)
      .SetMethod("subscribeLocalNotification",
                 &SystemPreferences::SubscribeLocalNotification)
      .SetMethod("unsubscribeLocalNotification",
                 &SystemPreferences::UnsubscribeLocalNotification)
      .SetMethod("getUserDefault", &SystemPreferences::GetUserDefault)
      .SetMethod("setUserDefault", &SystemPreferences::SetUserDefault)
      .SetMethod("isSwipeTrackingFromScrollEventsEnabled",
                 &SystemPreferences::IsSwipeTrackingFromScrollEventsEnabled)
#endif
      .SetMethod("isInvertedColorScheme",
                 &SystemPreferences::IsInvertedColorScheme)
      .SetMethod("isDarkMode", &SystemPreferences::IsDarkMode);
}
}  
}  
namespace {
using atom::api::SystemPreferences;
void Initialize(v8::Local<v8::Object> exports, v8::Local<v8::Value> unused,
                v8::Local<v8::Context> context, void* priv) {
  v8::Isolate* isolate = context->GetIsolate();
  mate::Dictionary dict(isolate, exports);
  dict.Set("systemPreferences", SystemPreferences::Create(isolate));
  dict.Set("SystemPreferences",
           SystemPreferences::GetConstructor(isolate)->GetFunction());
}
}  
NODE_MODULE_CONTEXT_AWARE_BUILTIN(atom_browser_system_preferences, Initialize);