The callback for `win.showDevTools()` has no arguments

[sysrage]

NWJS Version : 0.59.0
Operating System : Windows 10

Expected behavior

As per the NW.js documentation, the callback from win.showDevTools() should be returning a handle to the DevTools window.

Actual behavior

The callback from win.showDevTools() contains no arguments.

How to reproduce

1. Open the NW.js SDK build and manually open the DevTools window.

2. Enter the following into the DevTools console:

nw.Window.get().showDevTools(null, (devToolsWindow) => console.log(devToolsWindow));

3. Note that devToolsWindow is undefined.

[sysrage]

@rogerwang this is still an issue with 0.68.0. Can you please take a look?