Undecorate half-maximized windows does not work properly on Gnome 3.22.2

[crazyboycjr]

The behavior I expect is when the Undecorate half-maximized windows option is checked, the title bar should always be undecorated. But on my Gnome 3.22.2, the plugin do not work as my expectation.

So I try to read the source code in extension.js, and find three facts:

1. The function setHideTitlebar could not achieve this goal, so I should uncheck the option of 'use alternate method for hiding the titlebar'.
2. Gnome adapt to new size-change API, so the 'maximize' and 'unmaximize' event are canceled that we need to change the API to 'size-change'.
3. The variable max in function shouldBeUndecorated make the return value always be false.

Here is my extension.js.
Thank you for your kind reply.

[luispabon]

This fix has been submitted to extensions.gnome, awaiting review.