- Electron version: 1.2.2
- Operating system: Windows 10 @32bit

Following the docs for [`Tray.popUpContextMenu()`](https://github.com/electron/electron/blob/master/docs/api/tray.md) it's optional to pass a menu. So I'd expect the default context menu (the one I set w/ `setContextMenu()`) to pop up if called with no args.
At least for 1.2.2 / Win10 this ain't seem to be so. I bound `popUpContextMenu()` to the click-event but nothing happens. Passing the Menu instance I passed to `setContextMenu()` produces the desired result.

``` javascript
var myTray = new Tray( ... )
myTray.setContextMenu(myMenu)
myTray.on('click', function(){
    myTray.popUpContextMenu()  // nothing's happening whereas
    myTray.popUpContextMenu(myMenu)  // will do
})
```

atom/browser/ui/win/notify_icon.cc
}
void NotifyIcon::SetToolTip(const std::string& tool_tip) {
  
  NOTIFYICONDATA icon_data;
  InitIconData(&icon_data);
  icon_data.uFlags |= NIF_TIP;
  wcsncpy_s(icon_data.szTip, base::UTF8ToUTF16(tool_tip).c_str(), _TRUNCATE);
  BOOL result = Shell_NotifyIcon(NIM_MODIFY, &icon_data);
  if (!result)
    LOG(WARNING) << "Unable to set tooltip for status tray icon";
}
void NotifyIcon::DisplayBalloon(HICON icon,
                                const base::string16& title,
                                const base::string16& contents) {
  NOTIFYICONDATA icon_data;
  InitIconData(&icon_data);
  icon_data.uFlags |= NIF_INFO;
  icon_data.dwInfoFlags = NIIF_INFO;
  wcsncpy_s(icon_data.szInfoTitle, title.c_str(), _TRUNCATE);
  wcsncpy_s(icon_data.szInfo, contents.c_str(), _TRUNCATE);
  icon_data.uTimeout = 0;
  icon_data.hBalloonIcon = icon;
  icon_data.dwInfoFlags = NIIF_USER | NIIF_LARGE_ICON;
  BOOL result = Shell_NotifyIcon(NIM_MODIFY, &icon_data);
  if (!result)
    LOG(WARNING) << "Unable to create status tray balloon.";
}
void NotifyIcon::PopUpContextMenu(const gfx::Point& pos,